Career: After stints in various theatre, TV and film productions, Fillion moved to New York where he starred in soap opera One Life To Live, for which he was nominated for a Daytime Emmy Award. Other early roles came in Saving Private Ryan, Two Guys and a Girl, and Dracula 2000. He eventually landed the starring role as Captain Malcolm Reynolds in Firefly (which he now says was the best acting job he's ever had). He has leant his voice to various animated series and computer games including King of the Hill and Halo 3, but his most successful role to date has been eponymous mystery novelist Castle. Other projects include Desperate Housewives, Waitress, Monsters University and Percy Jackson: Sea of Monsters.

Career: Katic had guest roles in a number of well-known TV series in the early part of her career, including Alias, Dragnet, The Shield, ER, 24, Heroes and CSI: Miami. She has also starred on the big screen in The Spirit (2008) and Quantum of Solace (2008). Her big break came in 2008 when she was cast as Kate Beckett in crime drama Castle alongside Nathan Fillion.

Career: Early projects included A Relative Stranger, Poldark and Wilde, but it was his small part as Fifth Officer Lowe in James Cameron's blockbuster Titanic that got him noticed. The title role in miniseries Hornblower followed, making Gruffudd a star on both sides of the Atlantic. He impressed in the BBC's adaptation of Great Expectations, drama Solomon and Gaenor (for which he learned Yiddish) and children's hit 102 Dalmatians, before reprising Hornblower. He's also appeared in The Forsyte Saga, Man and Boy, Warriors and Ringer, and his healthy film career has included the movies Fantastic Four (and its sequel), Black Hawk Down, and historical drama Amazing Grace. In 2014, he began playing Dr Henry Morgan in American crime drama Forever.