“London. A city in western Europe. The sixties. The decade between the 1950s and the 1970s. A time of gangsters and geezers. But mostly gangsters. And mostly the Kray Brothers. Who were gangsters. In London. The city. In the Sixties. The decade.”

Seriously? Can we do something about this voiceover? Is there an off-switch? Brian Helgeland's far-too-glamorous adaptation of John Pearson's book The Profession of Violence: The Rise and Fall of the Kray Twins chronicles the rise and fall of Ronald and Reggie Kray. The London gangsters.

The film is narrated by Reggie’s weedy wife Frances (Browning), a woman who, despite Browning’s best efforts, has neither substance nor discernible personality traits to recommend her. Her weedy commentary runs the gamut from the blindingly obvious to the glaringly obvious. The Krays are gangsters. They do gangster things. They are brothers. One is crazier than the other.

This, alas, is entirely in keeping with a film that depends on shotgun-over-the-mantle of cinematography and squarely literal-minded musical cues. You going to the chapel to get married? Is that the Dixie Cups on the soundtrack? Yup.

Legend starts well, as rival gangs do battle to become the East End's top dogs. But after a terrific first half-hour, we're dumped in inertia, as Frances' narration saps all the life out of looming political scandals, celebrity chums and Ronald's propensity for ultraviolence.

Mostly, the film seems to exist as a showcase for Tom Hardy, who provides a soulful Reggie and a loony, broad Ronald. One performance is as impressive as anything he's done since Bronson; the other may have been inspired by Harry Enfield.

Uneven or not, Hardy is well worth a watch and the film, for all its flaws, makes for a solid, if not exactly thrilling entertainment. Whisper it: bring back the Kemp brothers.