A maverick cop returning to duty after a leave of absence. A boss who's willing to back him even if he takes her down with him. A femme fatale who's engineered a perfect crime. On paper, the BBC's new detective drama, Luther, doesn't sound as though it will be pushing the boundaries of the genre. But on the strength of a first episode preview, it looks as though John Luther could be the best new TV detective since Wallander (or at least the moodiest).

Without getting too involved in the details of the plot here, the first case that Luther investigates is a cold, twist-filled murder that soon becomes personal. Again, it doesn't sound incredibly original: but when you're playing in a field as overdone as a police show, it's all about the way you do it.

So let's move to the positives – and there are plenty of them. For a start, there's the cast. Idris Elba was brilliant in The Wire, had a good comic turn in the US version of The Office, and is about to show up as an awol special forces commando in The Losers, a summer action blockbuster. But Luther is the sort of role you imagine he's been hoping for since he was muscled out of The Wire.

As fans of Stringer Bell – the thinking man's drug dealer – will know, he's a commanding presence on screen, and it's great to see him getting to do something decent on British TV (although it's still a slight shock to hear him without a Baltimore drawl.) The same edge and intellect that he brought to Bell is in full effect, even if Luther is (mostly) on the right side of the law. Elba's got that gift of making you think there's something whirring away in Luther's brain when he's not talking: when he throws a pause into his sentences his sense of timing is immaculate; when he erupts in a scene with his wife, Zoe (Indira Varma), it's captivating.

Elsewhere, femme fatale Ruth Wilson laps up her lines like a cat sitting on the edge of a bath of cream and support comes from a cast that includes Stephen Mackintosh, Paul McGann and Warren Brown. The script is strong – albeit played out by a few too many cops with wobbly accents and dropped H's for my liking – and the fluid direction keeps the action involving. The use of a Massive Attack song in the credits sets the tone for a London that's given an intense, metropolitan noir feel.

The HBO question – namely, why British drama can't be as ambitious and compelling as The Sopranos, Six Feet Under, Deadwood, In Treatment or True Blood – has been niggling at British TV over recent years. It's an argument that touches on everything from funding, to talent, to ambition – and it would be premature to make any claims for Luther on the strength of this enjoyable first episode. But it's also difficult to avoid making the HBO comparisons when the show has such a notable Wire star as the lead. In addition, there are two other obvious HBO links in the cast – which suggests that the BBC is at least employing people who've got some of that magic HBO dust on their CVs. Indira Varma also starred in Rome (an HBO/BBC co-production) and Brian Kirk, the director of the first two episodes, has just finished work on Boardwalk Empire, Martin Scorsese's eagerly awaited drama due to air later this year.

• Luther will be on BBC1 on 4 May