Sienna Guillory (Resident Evil: Retribution, Inkheart, Love Actually, Eragon) has been cast to play Luther's new love interest in the third installment of Neil Cross' critically-acclaimed Dramaville mini-series, Luther, which started filming last week. Luther, set to premiere in 2013 on BBC AMERICA, is a BBC and BBC AMERICA co-production distributed by BBC Worldwide.

John Luther is back under intense pressure, with two conflicting crimes to investigate and a ruthless ex-copper determined to bring him down. Luther's life is his job; that is until love crosses his path and offers him a chance of happiness. Sienna Guillory plays Mary, who works in a vintage clothes shop. She meets Luther in a chance encounter. Here's what the actress had to say about joining the new season, which will consist of four 60-minute episodes.

"You realize why Luther is so good when you read Neil Cross' scripts, and then you meet Idris (Elba) and understand what 'untamed' means. There is no other set I'd rather be on, and I love the disastrous fun of being Mary Day, the right girl in the wrong place."

Series star Idris Elba also thanked the fans of this critically-acclaimed program.

"I want to thank the fans for waiting so patiently for the new season. We're thrilled to deliver it to you. Here comes John!"

Warren Brown (Inside Man) returns as DS Justin Ripley, Nikki Amuka-Bird as DS Erin Gray, Dermot Crowley as DSU Martin Schenk and Michael Smiley as Benny Deadhead. Further guest stars include Lucian Msamati (Game of Thrones) and Ned Dennehy (Tyrannosaur).

Luther star Idris Elba won the 2012 Golden Globe for Best Performance by an Actor in a Mini-Series or Motion Picture Made for Television. The BBC Executive producer is Phillippa Giles and the producer is Claire Bennett.