SARASOTA — When the police pulled 5-year Pok-nam Shin out of school, the little girl who now goes by Holly Hoyle O’Brien asked the only question that mattered: Where’s my daddy?

Her mother had died without leaving Pok-nam a single memory. Dad was all she had. He was an alcoholic who ran a grocery store and gave her money instead of affection. He had remarried but it didn’t last. One night, while he slept, Pok-nam awoke and peered in silence as her stepmother gathered Pok-nam’s younger half-sister, Eun-Sook, and made their getaway. They never returned.

The officer escorted the tyke to his car and drove her to where it happened. Dad had wandered into the path of a speeding train; Pok-nam’s job was to identify the body. She looked closely, and would never forget what she saw. As the distracted cops milled about the site, Pok-nam took off running. Her meandering path led to an orphanage in her native Pusan, South Korea.

For the next few years, the child without a family was treated kindly amid the company of strangers. Looking back in 2008, Holly the adult wrote a four-page single-spaced autobiography about her formative years there. She included this: “I finally got settled down into the orphanage along with all the other kids. At first I wasn’t sure why they had me taking care of babies and kids. Somehow I finally figured out that I was older than the other kids and I loved babies so much that I really didn’t mind at all.

“I felt like I was a big sister to them and when they were looking at me and I could see in their faces that they were proud of me that I was looking out for them. I guess it felt good inside that they were proud of me and I even loved them more.”

In 1978, at age 9, Holly was adopted by an American couple who gave her the new name. The transition to her home in Alexandria, Va., was bumpy — culturally and linguistically — but the environment was nurturing. Plus, she had three sisters and six brothers. But her dreamscape was haunted. One night she woke up in tears, and the things she kept bottled up came gushing out for her parents: “I said my daddy died, I have a sister, we need to find her.”

Holly’s mother contacted the orphanage. There were no records of a biological sister, anywhere. Decades later, Holly’s husband contacted the orphanage again, just to be sure. The results were the same.

“But in my heart, I knew,” Holly, 46, recalls. “I knew she was out there somewhere.”

•••

Eun-Sook Shin, now Meagan Hughes, was too young to remember her father. For that matter, she recalls little about her biological mother, or what happened to her. She has faint memories of a Korean orphanage. She was adopted by an American family in 1976, and grew up in Kingston, N.Y., not quite 300 miles from Alexandria.

Meagan’s family moved to Venice in 1981 on account of her father’s health problems. She graduated from Venice High School. But the death of her adoptive father, Edwin Craig, in 2006, altered the relationship between Meagan and her mother; the two are now estranged. Twice divorced, Meagan has two children, 12 and 19, and is in a long-term relationship.

A self-described “Chatty Cathy” frequently disciplined in school for talking too much, Meagan found her footing after working a receptionist’s desk. “I was spending too much time behind a computer and not enough time interacting with people, which is what I enjoy. I love to help people.”

Meagan qualified as a certified nursing assistant in 2002 and began her career in home health care. Her first patient was an elderly woman in a hospice program, which “was very hard,” Meagan recalls. “They said you have to separate your feelings from your work.”

Bottom line: Meagan moved on to Sunset Lake Health and Rehabilitation Center in Venice, where she got a job as a physical therapy assistant. That’s where, in 2012, she met Mathew Nelms, also a CNA and a physical therapist. They became friends, and both wanted to work at Doctors Hospital in Sarasota.

Late last year, Nelms accepted an offer from Bayfront Health Port Charlotte, just a 10-minute drive from his home in North Port. Six days before his orientation at Bayfront, Nelms was updating his resume and included a recent award for a high volume of positive patient feedback. Doctors gave him a call. In what would prove to be a most fateful twist, Nelms took the job last November.

“Before I left, Meagan said, ‘Do you think you can get me in there?’ I said, ‘I’ll try.’ ”

•••

Holly earned a CNA license in 1991 and latched on to a nursing home job in Virginia. She moved to Sarasota with her now ex-husband in late 2005. She worked for several years with HealthSouth Rehabilitation Hospital. “I had a tremendous experience with rehab,” recalls Holly, since remarried. “I really enjoy helping people. I’d worked in nursing homes before and I wanted to do more than that. I wanted to do new things.”

She applied at Doctors several times before finally getting on the payroll Jan. 7. She began work on the fourth floor, with the medical surgical unit.

“I met Holly in December,” recalls Julie Bennett, clinical nurse manager for the surgical unit at Doctors. “She had a very earnest quality about her, very service-oriented, so we hired her, and she’s been a great employee. But we also had Matt Nelms telling us about Meagan, you need to look at Meagan . . .”

Nelms told Bennett that Meagan had submitted a job application, and that it was worth a look. Bennett told him her hands were tied until she got more information from the recruiter. Weeks passed. Nelms was so persistent that Bennett finally queried the recruiter. The holdup was minor but significant in computer language. Meagan’s name had been misspelled: M-e-g-a-n.

Thanks to the reinsertion of the letter, Meagan was invited in for interviews. She aced the audition and reported for work on March 1. On the fourth floor. Same as Holly.

•••

“Obviously, we all form friendships at work,” says Jackie Gould, a Doctors staffer for 15 years, now director of the medical surgical unit. “We’re like a big family here, we share a lot of personal information with each other.” So it was no surprise when Meagan and Holly, hired three months apart, working the same 7 a.m. to 7:30 p.m. shift, hit it off. Especially after someone else made the first connection.

“One of the patients,” says Holly, “told me there was another nurse, named Meagan, who was from Korea. She said you should talk to her, maybe you’re from the same town.”

The coincidences began stacking up immediately: Korea, the missing family, “abandonment” listed on orphanage paperwork, adoption to Americans. “Holly would come up to me and say something like ‘Guess what? Meagan’s maiden name was the same as mine,’” says Bennett. “I thought, well, that’s interesting, but I still wasn’t getting it.”

Meagan and Holly would go to lunch together, meet after work, and compare notes on their dramatic similarities. Holly: “I was like, this is too good to be true. I said we’ve got to do the DNA test, it’s the only way we’ll get the truth out of the whole thing.” Holly ordered DNA kits from Canada and the orphans did mouth swabs. Holly dispatched the samples to Canada in early August.

The lab results returned to Holly via email on the afternoon on Aug. 17. She was on jury duty. The match was positive.

“I’m like, this can’t be,” Holly recalls. “I was trembling, I was so excited, I was ecstatic.” Holly called the lab for verbal confirmation. Then she texted Meagan. Meagan didn’t reply immediately. Holly called the fourth floor, shared the news, left the message for Meagan. And she reached out again.

“I was on vacation, we were driving to California,” Bennett says. “Well, my husband was driving, I was drowsy, and Holly texted me in the car, saying ‘You’ll never believe it, the DNA came back positive, Meagan’s my sister.’ I literally sat straight up, nudged my husband and woke the kids up in the back seat.”

Meanwhile, back in Sarasota: “When I heard from Holly, my first reaction was like, ‘Oh my god.’ I was in shock, I was numb. I have a sister,” says Meagan, still somewhat dazed, weeks later. “But I was with a patient. Fortunately, it was near the end of my shift. If she had texted me early in the morning, I don’t know what I would’ve done.”

•••

Astonishing personal and professional parallels between long-separated twins have been well documented amid lively debates on the power of nature over nurture. The connections between reunited non-twin siblings have been less scrutinized, but they are not unprecedented.

Consider the recent chance meeting of Lizzie Valverde, 35, and Katy Olson, 34. Valverde was adopted by a family in New Jersey; Olson was raised in Iowa and Florida. In 2013, they discovered each other in a creative writing class at Columbia University.

Born less than a year apart, teenagers Jordan Dickerson and Robin Jeter met for the first time since they were adopted to separate families 17 years prior. They almost literally ran across each other at a track meet in 2013 where they were competing for rival high schools in Washington, D.C.

In 2014, Emily Nappi and Mikayla Stern-Ellis traveled separately from their homes in California to New Orleans to pursue college studies at Tulane University. As freshmen, they wound up in the same dormitory; they even purchased the same fleece jacket at a Tulane Black Friday sale before they met. They discovered they were connected before conception — their biological father was a sperm donor from Colombia.

Social and behavioral scientist Nancy Segal, director of the Twin Studies Center at California State-Fullerton, has been addressing the phenomenon for decades in books and academic papers. Once soft-pedaled for its implications on “biological determinism,” the infant science of behavioral genetics has since entered the mainstream and is lately beckoning molecular biologists to explore the links between genes and human social behaviors.

“I do think that genetically based similarities,” states Segal — herself a twin — in an email to the Herald-Tribune, “are the social glue that draws and maintains these relationships.”

But on a planet of 7 billion people, how to account for the mystery of cascading events that set up an unlikely reunion of orphans, born half a world away, more than four decades ago, choosing the same profession, choosing the same hospital?

“Everything had to happen just right for them to meet, and the odds of that were like a miracle,” says CNA Nelms, still perplexed over his unwitting role as a bridge between the sisters. “I still can’t believe it.”

Unit manager Bennett’s credulity is equally strained: “We see people’s lives change on a dime up here. Every day, we see some of the most emotionally charged stories. But typically it’s with patients, not personnel.”

With no kids of her own, Holly has, in an instant, become an aunt with two nieces. The holidays will be different this year. Words seem inadequate. “I have this very strong belief that God must be . . .” Holly is speaking through tears now, Meagan at her elbow. “Like, whatever I’ve done, I must’ve done something good in my life.”

On the fourth floor of Doctors Hospital, staffers can only hang back in wonder as two sisters cling to each other and let it flow.