When Christel Wallace found a piece of paper folded up at the bottom of her purse in March 2017, she threw it in the trash. She hadn’t yet used the maroon bag, made by Walmart and purchased from one of its Arizona stores months ago.

But after a few minutes, she got curious. She took the paper out of the wastebasket, unfolding the sheet to reveal a message scrawled in Mandarin Chinese.

Translated, it read: Inmates in China’s Yingshan Prison work 14 hours a day and are not allowed to rest at noon. We have to work overtime until midnight. People are beaten for not finishing their work. There’s no salt and oil in our meals. The boss pays 2,000 yuan every month for the prison to offer better food, but the food is all consumed by the prison guards. Sick inmates have to pay for their own pills. Prisons in China cannot be compared to prisons in the United States. Horse, cow, goat, pig, dog.

Christel’s daughter-in-law Laura Wallace posted a photo of the note to Facebook on April 23. The post first went viral locally, getting shared and liked several hundred times, mostly by fellow Arizonans. After a few days, local media outlets picked up the story; a week or so after that, dozens of mainstream publications like USA Today and HuffPost followed suit. One video report on the incident accumulated 2.9 million views.

Shares of the note provoked shock and outrage. Even those who were skeptical of the note’s provenance were incensed, pointing to a wider issue. “Who cares if it’s a marketing stunt?” read one comment on Facebook. “If it made five people rethink buying cheap crap, then it’s a success.”

At the time, a Walmart spokesperson told a reporter in Arizona it was unable to comment because it had “no way to verify the origin of the letter.”

You may remember this story or one like it. It follows a long line of SOS-style notes found by shoppers. They crop up a few times a year, and each story follows the same beats.

First, a shopper in the US or Europe finds a note in the pocket or on a tag of a product from a big retailer — Walmart, Saks, Zara. The note claims the product had been made using forced labor or under poor working conditions. The writer of the note also claims to be in a faraway country, usually China. The shopper takes a photo of the note and posts it to social media. It’s reported on by all sorts of publications from Reuters to Refinery29, where the articles reach millions of readers.

Then the hysteria cools, and the story falls into the viral news abyss. There’s no real attempt at verification. There’s no meaningful corporate gesture. There’s no grand reckoning with the system of global production from which this cry for help is said to have emerged.

As for Christel’s particular Walmart note, there are a number of possibilities regarding who wrote and hid it, and its contents are difficult to fact-check. A Chinese prison called Yingshan may exist, or it may not. Forced labor may be practiced there, or it may not. A prisoner in China may have written the note, or maybe a Chinese activist did, or maybe an American activist instead. The note may have been placed in the bag in a prison factory, or somewhere else along the supply chain in China, or perhaps in Arizona.

The only way to make sense of this puzzle — one with actual human stakes that can help explain how what we buy is made — is to try to trace the journey backward, from the moment a note goes viral to its potential place of origin. Which is how I find myself in rural China, outside of a local prison, 7,522 miles away from where Christel first opened her purse.

Guilin is a city in the Guangxi Zhuang Autonomous Region of southern China, and a tourist haven, renowned for the tooth-like karst peaks that rise from the banks of the Li River. Its limpid lakes and limestone caves draw tens of millions of visitors every year.

To reach Guilin, it takes me two international flights, two taxis, a one-hour bus ride through border control, and three hours on a high-speed train. I travel from London through Hong Kong on to Shenzhen and then Guilin via the Guangshen Railway. There, I meet Channing, a local reporter hired to help me find the prison.

We’re in Guilin because of the first and only concrete lead in the Walmart note: the name of the prison. The note writer says the prison is called Yingshan, and several weeks of research has led me to believe it’s located in China’s Guangxi region, home to many manufacturing factories because of the area’s cheap labor and low taxes.

The very few details I can find about Yingshan prison come from a 10-year-old report on prisons across China written by a human rights group. The report suggests the prison may be in the suburbs of east Guilin, and so the plan is to explore the neighborhood, talk to locals, and look for signs — barbed wire, security cameras, anything.

But before we embark on our prison scouting, we have something else on the agenda: a visit to the city’s only Walmart store. It feels important, given the note was found in a Walmart, albeit one on the other side of the globe. Perhaps a Chinese Walmart close to where the note supposedly originated can provide clues, or at least context.

The Guilin Walmart is a 10-minute drive from the center of the city, spread across two floors in a shopping mall, on a road lined with scooter repair shops. Walmart is the world’s biggest retailer; it owns 11,700 retail units in 27 countries around the world, including Brazil and South Africa, under various banner names. In China, Walmart owns 389 Walmart Supercenters, in addition to 21 Sam’s Clubs and 15 Hypermarkets.

A note on Walmart’s Chinese site reads: “Walmart China firmly believes in local sourcing. We have established partnerships with more than seven thousand suppliers in China. Over 95% of the merchandise in our stores in China is sourced locally.”

The Guilin Walmart sells athletic shorts made in Vietnam, girls’ T-shirts made in Bangladesh, and sports jackets made in Cambodia. But for the most part, the store’s clothing is made in China, some of it just a few hours away. There are England football shirts and women’s purses from Guangdong, World Cup Russia sandals from Fujian, Frozen and Mickey Mouse tees from Shanghai, and baseball jerseys and Peppa Pig sun hats from Jiangxi.

Countries the world over encourage citizens to “buy local,” so why would China be any different? Still, necessarily, what is local to one place — local practice, local perspective — is foreign to all others. To those in the country, “made in China” means items produced by their fellow Chinese that contribute to the robust economy. Elsewhere in the world, particularly in the US, the phrase draws ire, conjuring images of goods mass-produced in factories with questionable conditions by workers who have supplanted their own country’s workforce.

Walmart in the US has tried and tested the homemade idea. In 1985, founder Sam Walton voiced a commitment to “made in America” products, launching a program called “Bring It Home to the USA” to buy more US-made goods. Around that time, according to reporter Bob Ortega’s book In Sam We Trust, Walton estimated 6 percent of his company’s total sales came from imports; a Frontline report found that number may have been closer to 40 percent. Bill Clinton, then the governor of Walmart’s home state of Arkansas, described “Bring It Home to the USA” as an “act of patriotism.” The program failed.

It’s easy to understand why. The “made in America” ideal comes second to finding the cheapest sources of production — this was true in the ’80s, and it’s true now. A study released in 2016 found that three in four Americans say they would like to buy US-made goods but consider those items too costly or difficult to find. When asked if they’d buy an $85 pair of pants made in the US or a $50 pair made in a different country, 67 percent chose the latter.

To those in the country, “made in China” means items produced by their fellow Chinese that contribute to the robust economy

Today, Walmart outsources the majority of its production around the world. According to a 2011 report in the Atlantic, Chinese suppliers are believed to account for around 70 percent of the company’s merchandise. A 2015 analysis from the Economic Institute, a progressive think tank, found that Walmart’s trade with China may have eliminated 400,000 jobs in the US between 2001 and 2013.

This is something Walmart says it’s trying to change. In its 2014 annual report, the company pledged to spend an additional $250 billion on US-made goods by 2023, saying it believes “we can drive cost savings by sourcing closer to the point of consumption.” Research from Boston Consulting Group projected this could create a million new US jobs.

At the initiative’s 2018 halfway point, though, it’s unclear how many jobs have been created or how much money has actually been spent. Additionally, in 2015, the Federal Trade Commission initiated a probe into Walmart’s mislabeling of foreign goods as “Made in the USA.” Walmart took action by removing inaccurate logos and making its disclosures more transparent, only to come under fire for deceptive “Made in the USA” labels yet again the very next year.

Forced labor is commonly practiced in the Chinese prison system, which the Chinese Communist Party first established countrywide in 1949, modeling it on Soviet gulags. The kind of crimes that land someone in the Chinese penal system range widely, from murder and bribery to saying anything remotely bad about the government. Freedom of speech isn’t a reality for Chinese citizens, who can face decades in prison for publishing articles about human rights online.

A tenet of the Chinese justice system is that labor inside prisons is good for the country. The government, as well as many of its citizens, believes it helps reform corrupted people — and China is far from the only country to use prison labor. The US legally benefits from labor in its prison system, and while not every US prison practices penal labor, hundreds of thousands of American inmates work jobs that include making furniture and fighting fires. In August of this year, prisoners from 17 states went on strike to protest being forced to work, characterizing the practice as “modern slavery.”

Peter E. Müller, a leading specialist at the Laogai Research Foundation, and his team extensively document the human rights abuses inside China’s prison system. This work includes identifying prisons and camps that employ forced labor, tracking the inmate population, and gathering personal testimony from those who have experienced forced labor.

He says prisoners in China, the US, and elsewhere are sometimes paid for their labor. (In the Walmart note, the writer describes forced labor and beatings, as well as low pay for long hours and health care deducted from payment.) The amount depends on the financial situation of the prison; the average pay in American state prisons is 20 cents an hour. Müller says the monthly salary specified in the note (2,000 yuan, or $295) is “unusually high,” but speculates that it may be because the prison “makes good money because of high-quality workers.”

Human rights organizations, such as the Laogai Research Foundation and China Labor Watch, say the biggest problem in stopping the export of products made in prisons is that the supply lines are “almost untraceable.” Supply lines, in general, are very difficult to trace due to the enormous complexity of supplier networks, a lack of communication between actors, and a general dearth of data that can be shared in the first place. The result is a frustratingly opaque global system of production.

Li Qiang, the founder and executive director of China Labor Watch, explains that American companies that manufacture abroad place their orders directly with factories or sourcing companies, and that those factories and companies can transfer the orders to prisons without the company’s knowledge. In fact, some of these relationships are formalized to the point where prisons that use forced labor have a sister factory that coordinates the prison manufacturing.

It’s essentially a front, as sister factories will use a commercial name for outside trade, intentionally mislabeling products that are made in prisons. Prisoners are never physically sent to the sister factories; the main bulk of the production happens on prison grounds. Once nearly complete, items are then sent to the sister factories, where they are prepared and labeled for international delivery. This system isn’t easy for companies to monitor. Suppliers conceal these practices from clients, and supplier checks are not frequent, especially for large corporations like Walmart, which use a large number of suppliers and subcontractors.

Qiang says the issue can feel intractable. “Even if shoppers in the US understand that the items are being made under poor working conditions, there is nothing they can really do,” he says. “Multinational corporations will not invest in improving their supply chain if there are few laws to protect workers whose rights are being violated, and no successful lawsuits against brands, companies, or their factories for violating them.”

On a Tuesday morning in late May, Channing and I sit at a table in our hotel lobby. We browse message boards on Baidu, one of the country’s most popular search engines and social networking sites, to see if the issue of prison labor is discussed on Chinese social media, or if it’s a subject the government censors.

In a matter of seconds, Channing is able to find discussion boards filled with suppliers looking to outsource labor to prisons. The conversations are quite ordinary — there is no coded language, and full addresses and contact numbers are included in postings. We also find dozens of posts from people offering the services of prisons they work with to mass-produce items for overseas companies, including “electronic accessories, bracelets, necklace bead processing, toy assembly, and shirt processing.”

One post in Chinese reads: “Because our processing personnel are from prison, it has the following advantages. The prison personnel are centralized and stable, and they are managed by the prison. There is no need to worry about the flow of people and the shortage of labor. The processing price is low: Since the processing location is in prison, there is no need for manufacturers to provide space and accommodation; and the prison works in the principle of serving the people, so the processing price is guaranteed to be absolutely lower than the market price. If your company needs it, please contact!”

In an effort to verify not only that Yingshan prison exists but also that it’s one of many Chinese factories that use forced labor and contract with manufacturers, Channing and I drive toward the suburbs in the eastern part of Guilin.

Channing asks our driver to drop us at a high school so we can remain undetected. Nearby, I’d marked a spot where I believed the prison to be according to the human rights report I’d found before arriving in China. But the prison isn’t there. In its place is a crossing, though there’s reason to believe the prison is closed — a dilapidated sign pointing left reads: Yingshan.

We walk down the road and find the area under heavy surveillance. Security cameras are hitched onto poles on every corner of the pathway. The farther we walk, the more literal the warnings that we shouldn’t be there. Three different signs hammered into a tree read: “DO NOT APPROACH.”

Yingshan prison, described in a note found in a Walmart handbag thousands of miles away in the US, does exist — and we are standing in front of it.

Though it had been difficult to find, it actually doesn’t seem so hidden after all. It is integrated into the neighborhood, just around the corner from a driving school, near leafy streets and apartment blocks.

The prison doesn’t look like an archetypal prison you’d see in the US. If it weren’t for the two security watchtowers, Yingshan could be mistaken for a modern residential building. Thick bushes cover dark blue metal fences lined with barbed wire. The high walls are painted cream with decorative white lines demarcating each of the building’s five floors. Each window has a neat white frame, with a metal air vent attached.

Several guards in uniform are standing in the parking lot of the building next door. We don’t approach them for fear of being detained. The Chinese government treats both domestic and foreign journalists hostilely. Reporters are often banned from entering the country, and they have also been detained for their work. Our safest bet for gathering information is to speak to people in the area who may have ties to the prison.

Walking down a second pathway that runs alongside Yingshan, the village of Sanjia comes into view. Sanjia is a small village that abuts the prison grounds. In the village, crumbling homes stand alongside gated, modern ones painted gold. Locals say this is because the land is being bought out, and that the village is grappling with redevelopment.

Each person we speak to has a personal connection to the prison. They know people imprisoned, have a family member working inside, or have worked inside themselves. They tell us that guards who work in Yingshan are housed with their families in an apartment complex next to the prison. We realize this is the building with the parking lot filled with uniformed guards.

Zhenzhu, who asked that her surname not be used for fear of retribution from the government, can see the prison from her front door. A jovial woman, she has lived in the village for 14 years, moving to the area right after she was married. As we talk, we hear pigs squealing. Zhenzhu explains that those are her pigs, 100 of them, next door in a slaughterhouse she runs with her husband.

When the building of the prison commenced in 2007, Zhenzhu was three months pregnant, and her husband was employed as a construction worker on the project. By the time their daughter turned 3, the building was complete. Zhenzhu has visited the prison before, to see an inmate; Yingshan allows visits from family members under heavy security. She says its walls are buried so deep into the ground that “even if the prisoners want to break out by digging an underground tunnel, they can’t dig through.”

Yingshan prison, described in a note found in a Walmart handbag thousands of miles away in the US, does exist — and we are standing in front of it

Zhenzhu recounts much of what her husband told her about his experience at Yingshan. For years following the construction, he would visit for maintenance checks and additional building; trucks were always driving fabric in and out of the prison. The trucks, he told Zhenzhu, were from factories located in the Guangdong province. Guangdong is home to an estimated 60,000 factories, which produce around a third of the world’s shoes and much of its textiles, apparel, and toys.

Everyone we speak to, Zhenzhu included, says they’ve seen labor inside the prison or have been told about it directly by inmates. None were familiar with Walmart goods being produced there, but some could confirm that women’s fashion is manufactured inside.

To those in the village, prison labor is not just common knowledge; it’s also necessary. They consider the prisoners “bad guys” who have committed horrible crimes. In their eyes, the labor is a good thing: It helps rehabilitate inmates and gets them to understand the value of work. But that work can come at a great cost. According to local hearsay and furthered by a published account from a woman who was married to a Yingshan prison guard, inmates have been known to kill themselves because of the poor conditions and forced labor.

Zhenzhu leads us around the edge of the village, to get a side view of the prison. She points to the building we first passed and tells us that’s where the inmates eat and sleep. She then points to a building farther in the distance on the left that looks almost exactly the same. It’s also painted cream, but with slightly larger white window frames; a yard obscured behind the prison wall separates the structures. The second building, she tells us, is for “the work.”

The Walmart note followed a tradition of hidden messages found by shoppers. In 2014, shoppers found labels stitched into several items of clothing in Primark stores across the UK. The labels, written in English, read: “forced to work exhausting hours” and “degrading sweatshop conditions.”

As the notes spread across social media, the fast-fashion company conducted an investigation and found the labels were fake. The company said the items were all made by different suppliers, in different factories, on different continents. They stressed it was impossible that the same labels, especially those written in English, would appear on all the items and that they believed the labels were part of an activist stunt carried out in the UK.

Though no one claimed credit for the labels, activist groups had been waging campaigns to protest Primark’s labor practices in the time leading up to their discovery. War on Want led a 2013 campaign against the company after more than 1,100 people died as a result of the Rana Plaza collapse. Primark, along with J.C. Penney and Joe Fresh, was among the retailers whose products were made in the Bangladeshi complex.

Almost all the messages that have been found in stores have come under public scrutiny, as they’re often suspected of being written and planted by activists. The handwriting, the language, and even the paper used for notes have pointed to activist work. For example, several notes and labels, like the Primark ones, were written in English. Many inmates and factory workers in China, as well as Bangladesh, come from poor backgrounds and are unlikely to have had the chance to learn English in school.

There have been, however, at least two instances in which actual workers have claimed the notes. In 2011, a shopper bought a box of Halloween decorations at an Oregon Kmart. She found a note inside the box, allegedly from a prisoner in China explaining that he had made the item under forced labor conditions.

Two years later, Zhang — a man who asked newsrooms to only use his surname for fear of being arrested and imprisoned again — claimed to be the writer of the note. He said he planted 20 such notes during the two years he spent in prison, with hopes they would reach American stores. His handwriting and modest English language proficiency matched those of the note, but even then, it wasn’t feasible to fully corroborate his story. As the New York Times wrote, “it was impossible to know for sure whether there were perhaps other letter writers, one of whose messages might have reached Oregon.”

The second instance came in 2014, when a shopper in New York found a note in a Saks shopping bag she received when purchasing a pair of Hunter rain boots two years earlier. The note, written in English, claimed to have been written by a man in a Chinese prison; it also included his email address, photo, and name, which led to the finding of the alleged author, Tohnain Emmanuel Njong. Originally from Cameroon, he said he’d been teaching English in China when he was arrested in May 2011 and wrongly jailed for fraud charges.

In both cases, the final step of verification would be to confirm with the prisons mentioned in the notes that Zhang and Njong served sentences at their facilities and that forced labor occurs there. But since Chinese prisons refuse to provide comment on such stories, there’s little way of definitively confirming the prisoners’ accounts.

In 2017, the validity of hidden notes came into question yet again. Shoppers in Istanbul found tags inside clothing items in a Zara store that read: “I made this item you are going to buy, but I didn’t get paid for it.”

It turned out Turkish workers, who produced the clothing for Zara in an Istanbul factory, planted the notes in protest. The factory where they had been employed closed down overnight, leaving them suddenly without jobs or a source of income. The workers wrote notes urging shoppers to pressure Zara into giving them the back pay they were owed. They then went to a Zara store in the center of Istanbul and hid the notes in the pockets of clothing being sold inside.

“When we think we’re not getting movement from companies, we turn to confrontational tactics like this”

The Turkish workers didn’t come up with the idea of the notes on their own. The Clean Clothes Campaign and its alliance partner Labour Behind the Label (LBL), an organization that campaigns for garment workers’ rights, helped plan the action.

LBL and other campaign groups have organized “note droppings” like this in retail stores like Zara for many years. The notes describe how poor labor practices are behind the store’s items; LBL gathers information about these practices through its own reports and interviews.

“Dropping notes is an extension of leaving leaflets in stores,” says LBL’s director of policy Dominique Muller. “When we think we’re not getting movement from companies, we turn to confrontational tactics like this.”

LBL doesn’t worry that the notes they plant in stores could overshadow any potentially real notes found in stores. “These notes are just a drop in the ocean. They’re still new” — as an activism tool, that is — “and they will continue to have an impact.”

As of this June, the Turkish workers had only received partial payment.

Finding Yingshan brought some answers about the validity of the note. For one, the prison named in the Walmart note exists. We heard firsthand accounts from locals who said forced labor does occur inside the prison as the note described. What we were told about the work is that the hours are long, the work is done indoors, and the labor involves manufacturing fashion items, which might include bags like the purse Christel bought in Arizona.

After Walmart issued its statement about there being “no way to verify the origin of the letter,” the company launched an internal investigation. It was found that the factory that made the purse didn’t adhere to Walmart’s standards, which stress the need for “labor to be voluntary” and state that “slave, child, underage, forced, bonded, or indentured labor will not be tolerated.” As a result, the company cut ties with the supplier, a decision the company only disclosed after it was contacted for this story. Walmart declined to clarify whether the supplier in question had contracted with Yingshan prison.

In a statement to Vox, a Walmart spokesperson wrote: “Walmart has strict standards for our suppliers, and they must tell us where our products are being made. Through our investigation into this matter, we found the supplier’s factory sent purses to be made at other factories in the region that were not disclosed to us. The supplier failed to follow our standards, so we stopped doing business with them. We take allegations like this seriously, and we are committed to a responsible and transparent supply chain. There are consequences for our suppliers when our standards are not followed.”

One last question did remain unanswered. Was the note written by an actual prisoner, or by an activist with knowledge of the conditions that produced the bag? Müller of the Laogai Research Foundation believes the note is indeed real.

The description and details referenced in the note, he says, mirror much of what he’s heard in interviews with former prisoners. He says the language, the style of writing, and the use of the phrase “horse cow goat pig dog” — a common expression in China that compares the treatment of prisoners to that of animals — add to its authenticity. He believes the writer of the note certainly risked his life to send his message.

Even if the note is real, though, what’s come to light during the reporting of this story is that the Walmart note won’t end forced labor in China. The government is not going to release a public statement condemning human rights abuses inside its prisons because of stories like this one. It doesn’t see forced labor as a human rights abuse; Chinese citizens who don’t support the practices risk arrest if they speak out, and so most won’t.

The pitfall of pinning reform on awareness is expecting a bad thing to end if enough people know about it. Very rarely does mass attention on an issue result in a tangible shift in how things work. If merely sharing information were enough, the countless viral stories about forced labor recounted here would have already resulted in widespread reform.

Still, the incremental change the Walmart note led to — however impossibly small, however seemingly inconsequential — is a step. It has to be.

Additional reporting by Channing Huang.