Harry Potter star Tom Felton has interviewed his most obsessive fans, including Tina, who has stood outside nearly every event he's attended in seven years.
It was part of a BBC documentary into obsessive superfans, and why they go to such extreme measures to prove how much of a fan they are.
Who else counts as a "superfan"? In this show we meet a man who has a tattoo of J.K. Rowling's signature, and a woman who proposed to Tom.
However what is most interesting about the show are the interviews with the cast and author of Harry Potter, who express how it feels to have been the obsession of so many people for a great deal of their lives.
The interviewees include J.K. Rowling, Rupert Grint, and Daniel Radcliffe.