Andrew Tiernan has featured in a string of successful films including Guy Ritchie's Lock Stock & Two Smoking Barrels, Julian Simpson's The Criminal, Antonia Bird's Face, Piotr Szkopiak's Small Time Obsession, Nicolas Roeg's Two Deaths, Neil Jordan's Interview with the Vampire and Rob Green’s The Bunker. He first came to prominence as Piers in Derek Jarman's film of Edward II.

On television, Tiernan gave one of his most compelling and disturbing performances as the murderer in ITV's Cracker. No stranger to police dramas, he also appeared regularly in Lynda La Plante's Prime Suspect, on the other side of the law as DC Rosper. More recently he has been seen in Antonia Bird’s Rehab.

While working on Mr In-Between, Tiernan was much in demand. He had a particularly gruelling schedule, flying back and forth from London and Berlin, where he was appearing in the new Roman Polanski feature The Pianist. He comments: "I really felt like Mr In-Between!"