In this “notorious true story of the Kray twins” — the gangster brothers who briefly fancied themselves as kings of London in the ’60s — the knockout punch isn’t dealt by Tom Hardy raised to the power 2. It is the Kray mother (Jane Wood) in her bedraggled nightgown, mousey hair, wrinkled cleavage, and a firm grip passing along cups of tea.

Legend has all the elements of a period gangster film in place, along with dollops of additional dash and verve. It is stylish (the brothers are almost always in bespoke suits) and slick but somewhere down the halfway mark, takes a fearsome, dark twist. But more than anything else, it is a showcase for the formidable acting talents of Tom Hardy, last seen in the huge hit, Mad Max: Fury Road.

This is a reality driven film, brutish in evocation and as such, might not be pleasing to all.

Ultimately as a demo for showing Hardy’s range on screen, Legend is a fairly good attempt but as a gangster epic this is neither fun nor deeply nuanced. A far more capable filmmaker could have made this film live up to its title.

Though Helgeland’s writing is frequently funny and the period detail immersive, the film suffers for lack of someone to root for. The only sympathetic character is Frances, who—in an uncharacteristic move—is entrusted the voice-over.

The focus on the inner world of the Krays and their cohorts excludes any awareness of what else was going on in London at that point, but as a platform for the talented cast, especially Hardy, the movie works just fine. Helgeland’s screenplay is packed with sharp one-liners and repartee, including Ronnie’s observation that he is a “giver and not a receiver” when he is describing the kind of gay man he is, and Thewlis’s resigned comment that the gang needs “a public relations department and we have Joseph Goebbels”.

Sure, the Krays are dynamic in and of themselves, but a lack of a narrative drive as well as dangling subplots that never really take off, all amount to a much longer affair than you’d expect.

And with fewer punches than you’d expect.

Ultimately, it all comes back to Hardy’s performance.