Luther, Series 2, BBC One

LUTHER, BBC ONE Idris Elba's unconventional detective returns for a third series next month

A year ago when Luther battered down the door like a wailing banshee in bovver boots on day release, it was all a bit underwhelming. People shrugged and wondered whether Idris Elba was condemned to roam in eternal script limbo. They weren’t at all sure about Ruth Wilson’s parricidal astrosphysicist, all beestung, flame-maned and frog-boxed. If it started loopy, across six episodes it got ever so subtly loopier until its audience began to accept it for what it was: somewhere between a thuggish police procedural and Alice Through the Looking Glass. NB Wilson’s character was called Alice. She still is.

Yes, her usefulness as a plot device has long since expired but she and Luther have a thing going and scriptwriter Neil Cross is not about to call time on a beautiful relationship, however nonsensical. Alice is walled up in an institution, her wrists wrapped in bandages to stop her slashing herself out of the script. “Fewer than a hundred attempts,” she says. She does nothing by halves, does Alice (Ruth Wilson pictured below), and still harbours schizzy delusions about the big bearded cruiserweight with the rolling shoulders in the overcoat. To be fair, DCI Luther gives her every cause. He dropped in on her asylum last night for a chat, before making his excuses, there being a madman to reel in. “Need any advice?” she offered. “No,” he said, “pretty up to speed with my lunatics.”

The madman currently on the loose is a performer (Lee Ingleby, pictured below). A spindly figure with a thespian disposition and a burning interest in London’s history, he slithers up on his victims, mostly attractive young women, wearing a Mr Punch mask, does a theatrical amount of slashing and slicing, then makes eyes at the CCTV. Or even brings his own camera along to broadcast his antics live to the police. All very RADA. As usual we soon know who he is, as usual he’s an absolute fruitbat and as usual Luther has his number. All that needs to happen now is he’s got to make an arrest, but not too quickly: we must have our fair share of Grand Guignol. Having listened carefully to the dialogue, put some money on the Huguenots enjoying some sort of a plot function.

Apart from three fresh corpses, what’s new this time round? So far not so much. Luther has been crowbarred back into his old job having been exonerated of killing his wife. Only he’s advised by his boss (Dermot Crowley) to keep on the straight and indeed the narrow. “I can’t have the wheels come off this thing,” DSI Schenk told him, cueing up Speech No 63 from the Handy Book of Things Cops Say to Each Other on TV But Weirdly Not Down at Your Local Nick. “I fought tooth and nail to get you back.” Meanwhile, anyone and everyone is still helpfully drawing attention to the trainwreck that is Luther's private life. Business as per. He went to pick up a working girl who allows herself to be filmed being gangbanged while unconscious, and even she tried to suggest that her life’s more sorted than his. Cop anoraks may wish to note that Kierston Wareing, currently being butch and aggressive in jeans and leathers in The Shadow Line, is striking similar attitudes in a leopard-print coat. (She's changed her outfit, but not her spots.)

Last night’s opener ended on a nicely chilling note, Mr Punch cropping up where least (ie most) expected. He’s clearly some kind of Zen master at entering the backseat of a car without triggering the overhead light or even making a sound. But that’s contemporary Gothic for you. You wouldn't employ Luther to catch any of the regular druglords in The Wire. But it should be fun watching him go about his implausible work.