The amnesia plotline in “The Rook” may seem like just another TV trope — but it’s something that actually happened to series star Emma Greenwell.

“When I was 19 I had an accident where I had a bad concussion, which meant I had short-term memory loss,” says London native Greenwell, 30. “So I lost two weeks of my life. And I remember the … real feeling of discombobulation.”

“The Rook,” premiering Sunday on Starz (8 p.m.), is based on Daniel O’Malley’s 2012 bestselling book of the same name. Think “Men in Black” meets “X-Men” with a dash of “The Bourne Identity” thrown in. The series was originally developed by author Stephenie Meyer of “Twilight” fame, but she left early on due to creative differences.

“They were going in a different direction [from Meyer],” says Greenwell. “It is a young adult novel, and this is much more of an adult TV show [and] the supernatural is a subtle undertone. I had no involvement with Stephenie Meyer. I’m a huge fan, she’s a brilliant woman, but they went in a different direction.”

In the series, set in London, Greenwell’s Myfanwy (pronounced “Miffany”) wakes up on the Millennium Bridge surrounded by bodies, with no memory of what happened or who she is. She soon finds recordings and messages from her past self explaining that she’s part of a mysterious government organization called the Checquy that works with people with supernatural abilities— and she was attacked by one of her own.

“There’s many different things going on, but the [plotline] is how was Myfanwy’s memory taken and why, and her journey to figure out all of those questions,” says Greenwell.

Since some people on “The Rook” have supernatural abilities, Greenwell dove into comic book research. There, she drew inspiration from an unlikely source.

“I really got sort of sucked into the whole idea of the Hulk, the premise that he is very afraid of his own power,” she says. “For my character, I realize quite quickly that I have some sort of power — but I have no idea how it manifests and how in-control of it I am.”

The show co-stars Joely Richardson (“Nip/Tuck”) as Myfanwy’s no-nonsense boss and Olivia Munn (“New Girl”) and Ronan Raftery (“The Terror”) as fellow agents in this shadowy secret service. Greenwell says she enjoyed working with Richardson (who’s the sister of the late Natasha and the daughter of Vanessa Redgrave).

“She’s absolutely amazing. I was so intimidated initially to meet her. She’s a big deal in the UK and everywhere,” she says. “But she was so cool [and] I asked her a lot of questions. She’s incredibly supportive.”

Unlike many shows these days, “The Rook” did not film in Vancouver, but in London. And Greenwell says it was a treat to film in her native stomping grounds. “We filmed at Somerset House, the Natural History Museum, outside the Tate Modern,” she says. “We somehow filmed at literally every iconic London location. When we were filming in the natural history museum I was running around like, ‘My 4-year-old self is so excited!’”

Myfanwy is a Welsh name, but Greenwell initially mistook it for something else.

“When I first read it, I’m a bit dyslexic, and I was like, ‘My fanny?’ In England the fanny is [genitals] so I was like ‘I suppose it’s female empowerment?’ But of course I was very wrong!”