In July of 2016, Donald Trump, Jr. met a 42-year-old Russian attorney named Natalia Veselnitskaya who had promised him damaging information about then-candidate Hillary Clinton. One of his father’s contacts, a music publicist named Rob Goldstone, had arranged the meeting as a favor to a client of his, the Azeri real estate developer and pop singer Emin. Goldstone had worked with the Trumps on the 2013 Miss Universe pageant in Moscow. There were other reasons to take the meeting, too: Emin’s father, Aras Agalarov, is the 51st-richest man in Russia and an instrumental figure in the President’s aborted foray into Russian real estate: the Moscow tower he tried—and failed—to erect.

Trump Jr. has said he knew absolutely nothing about Veselnitskaya before their meeting, not even her name. She turned out to use the promise of information that could help his father’s campaign as a pretext to discuss reinstating a popular Russian-American adoption program, according to his version of events. What could be more harmless?

In fact, Veselnitskaya was already a key figure for the defense in one of the most notorious money-laundering scandals in recent memory, encompassing $230 million in public funds allegedly stolen from the Russians by a network of corrupt bureaucrats and routed into real estate sales, including some in Manhattan, through ironclad Swiss bank accounts. And she was accused of lobbying U.S. officials for a Russian NGO that sought to overturn the Russian ban on U.S. adoptions, according to a complaint filed with the U.S. Justice Department and Sen. Chuck Grassley (R-IA).

Veselnitskaya’s Facebook page paints a picture of a conservative Russian woman eager to defend her government from insults, hawkish on Israel and deeply concerned about American politics. “Liberalism is a fucking mental disorder,” she wrote on July 1, 2016—American liberalism. She also had derisive remarks for Brooklyn-born Muslim organizer Linda Sarsour and crusading former acting Attorney General Sally Yates, who was ousted by Trump. “The current U.S. Attorney General (Sally Yates) stated that all lawyers working for the government do not have the right to defend the government and trump orders!” Veselnitskaya wrote on Jan. 31. “In such cases, the general should resign.”

Veselnitskaya received her degree from Kutafin Moscow State Law University in 1998. In 2013, she agreed to represent Denis Katsyv, the son of Russian railroad baron Petr Katsyv and owner of the Prevezon group. The younger Katsyv was accused of collaborating with corrupt Russian officials in the money-laundering scheme. Then-U.S. attorney and “Sheriff of Wall Street” Preet Bharara led the charge against Prevezon; the company, his office said, had used cash from the theft to buy condos in Bharara’s jurisdiction.

Katsyv had been Veselnitskaya’s highest-profile client by far, and his defense would be a world-historic success not just for the wealthy real estate investor, but for the Russian establishment under President Vladimir Putin.

Until this weekend, the closest Veselnitskaya had come to the public eye was as a footnote to the compounding scandal of the Prevezon affair. Veselnitskaya had come to the United States with Katsyv, who was to be deposed by Bharara’s team. Not only wasn’t she deposed herself, she didn’t attend her client’s deposition in person. But after the deposition, she moved to the Plaza Hotel for the remaining two nights of her stay at a cost of $995 per night. Her firm then billed the U.S. government for the entire stay, as well as a single meal for five that included eight grappas, two bottles of wine, eighteen dishes and a bill that came to nearly $800. The group’s total expenses topped $50,000, and they promised to file more.

The legal proceedings in which Veselnitskaya was enmeshed contain a spy novel’s-worth of twists, turns and tragic, suspicious accidents. Sergei Magnitsky, a whistleblowing accountant who called attention to Russian bureaucrats’ alleged widespread embezzlement, was arrested and detained without trial for nearly a year until his death in 2009 from what prison staff described as “pancreonecrosis, ruptured abdominal membrane and toxic shock,” according to the U.S. government’s suit against Prevezon. The Russian Interior Ministry later revised the cause of death to heart failure. When Magnitsky’s family examined his body, they found bruises and that his fingers had been broken, according to an early draft of a report by then-president Dmitry Medvedev’s own investigative committee.

The incident led to a controversial piece of legislation: 2012’s Magnitsky Act, which sanctioned 18 Russian officials believed by the US to have been involved in Magnitsky’s death. Five days later, the Russian parliament voted to ban adoptions of Russian children by Americans, a move understood to be retaliation for the Magnitsky Act. Putin, by that time president of Russia again, also began to compile an “anti-Magnitsky” list of his own, according to the New York Times. Bharara was among the prominent names on it.

Trump Jr.’s conversation with Veselnitskaya, to his disappointment, focused on “a program about the adoption of Russian children that was active and popular with American families years ago and was since ended by the Russian government,” he said in a Sunday statement. That may be a roundabout way of saying Veselnitskaya wanted to discuss sanctions on Russian officials. Veselnitskaya campaigned unsuccessfully to keep Magnitsky’s name off the punitive 2012 law, according to the Times, and then, through an NGO called The Human Rights Accountability Global Initiative Foundation (HRAGIF), to have it repealed, supposedly for the sake of Russian children who could find American homes if the adoption ban were lifted in response.

The latter activity got Veselnitskaya some unwanted attention. She is not named on HRAGIF’s list of lobbyists under the Lobbying Disclosure Act, but she was accused of lobbying U.S. politicians, according to an email provided to Sen. Grassley by Hermitage Capital in a complaint (Magnitsky was at work for Hermitage CEO William Browder when he discovered the alleged money-laundering scheme). HRAGIF listed only two lobbyists, one of whom is Renit Akhmetsin, the former agent for the Russian FSB security service who in April met with Rep. Dana Rohrbacher (R-CA) in Berlin to discuss Prevezon. Russian friendliness to Rohrbacher has been a bone of contention with the FBI and the butt of “jokes” from Rohrbacher’s fellow Republicans. House Majority Leader Kevin McCarthy (R-CA) told colleagues in an audio recording that surfaced in May: “There’s two people I think Putin pays, Rohrabacher and Trump.”

Magnitsky’s death, and the original theft by Russian bureaucrats, are believed by many, including Sen. John McCain (R-AZ), to be the work of the Klyuev Group, a network of criminals working in the Russian government to enrich themselves at the expense of Russian citizens (its exploits are chronicled in English in a number of articles by reporter Michael Weiss). Magnitsky and others sought to expose what they believed was hundreds of millions of dollars’ worth of graft by the group.

The suit against Prevezon never went to trial. On March 11, Donald Trump fired Bharara, and on March 21, Nikolai Gorokhov, the Magnitsky family’s attorney and a key witness for the prosecution, fell from the fourth floor of an apartment building, apparently when a rope broke while he and others were trying to move a bathtub in through the window. He sustained head injuries.

The United States settled its case against Prevezon and its associated companies in May for $6 million, a fraction of the judgment a guilty verdict would likely have brought. Veselnitskaya declared victory on Facebook: “[A] 4-Year-old battle of the American State with a Russian citizen is over. With the Russians,” she wrote on Facebook.

This post has been updated.