One year on from series one, Belfast city centre is awash with drugs and beset by street crime. Our response officers Grace, Annie and Tommy are no longer wide-eyed rookies, and are beginning to feel the personal and psychological effects of relentless and punishing police work.

One of the stars of Blue Lights is Andi Osho, who is better known for her acting these days but has also been a successful stand-up, winning the Funny Women Award in 2007.