National Treasure review: a cracker from Robbie Coltrane

We’ve grown wearily accustomed to seeing our childhood TV heroes hauled up in court on charges of rape and sexual abuse, allegedly committed while they were at the height of their careers. While they kept us entertained on the small screen, it seemed that behind the scenes they were abusing vulnerable young people for their own entertainment. The sight of an 84-year-old Rolf Harris leaving court after being convicted for indecent assault on girls aged eight to 19 in the 1960s, 1970s and 1980s was the tipping point. We’re not shocked anymore, just waiting with resignation for the next episode of this tragic, twisted saga, when another kids’ idol or housewives’ favourite comes tumbling off his pedestal.

Robbie Coltrane is one of television's acting and comedy treasures, but his latest role, as a comedian accused of historic sexual offences, is his most daring and challenging in 20 years. National Treasure (Tuesday, Channel 4) is a drama in three parts inspired by the high-profile celebrity sex-abuse cases that have dominated the headlines in recent years, and by the work of Operation Yewtree, which exposed the prolific crimes of Jimmy Savile.

Coltrane plays veteran comedian Paul Finchley, whose best years are long behind him, but whose worst nightmare is about to come knocking at his quiet, suburban door. We meet him at an awards ceremony, where he’s nervously waiting to go onstage. The camera closes in on him as he takes deep breaths, fixes his jowly face into a grin, and steps out into the limelight. Over the next hour, we’ll get to know every wrinkle, every fold of skin, every crevasse of Coltrane’s face as we accompany him on his journey into hell. It’s a neat trick, pushing us so uncomfortably close to the character - we find ourselves watching his every expression and facial tic for a clue as to whether he’s guilty or innocent, but we also feel a strange empathy with him, as if we’re experiencing what it’s like to be accused of terrible crimes - or what it’s like to see your past catch up with you. “They think I’m fucking Jimmy Savile,” he mutters. By the end of this first episode, we’ve gone with him through the gamut of emotions, but we’re still no closer to the truth.

This is an astonishing performance from Coltrane, and it comes after a long period when the actor was pretty much off our screens. He enjoyed a decade of movie fame as Hagrid in the Harry Potter movies, but he's also gone through a divorce and has been suffering from health problems - the walking stick Finchley uses is not just a prop. This performance brings us right back to Coltrane's stunning turn as the troubled criminal psychologist Fitz in the 1990s series Cracker. Coltrane wasn't afraid to confront some dark, disturbing truths in that series, and he's not afraid to face up to a very modern bogeyman here. When asked if he was worried that taking this role might put the spotlight on his own past, Coltrane said he wasn't because he had done nothing. When Finchley asserts, "I didn't do this," you realise that this is not about whether he's innocent or guilty. It's about the terrible dilemma facing his family, friends and colleagues - whether to believe him or not.

Julie Walters is wonderfully torn as Finchley’s wife, Marie, who tries to remain loyal through all her doubts and suspicions, and Andrea Riseborough is brilliantly damaged as their daughter Danielle, a recovering addict who clearly still has issues with her father. Whatever happens over the next two episodes, my belief in Coltrane has been well restored.