It takes a double shot of Tom Hardy to truly electrify the new crime thriller, Legend. Darkly funny, patchy, but entertaining as hell, Legend is an overly Scorsese-ized biopic scripted and directed by Brian Helgeland, who also directed 2013’s 42 and adapted the screenplay for Mystic River.

Helegland’s movie’s big attraction, though, is Hardy’s full tilt performances as both Ronnie and Reggie Kray, the real-life identical twin London gangster overlords who terrorized East Enders during a ‘60s era reign of gunplay, stabbings, extortion, hostile takeovers and general dirty deeds. The publicity-hungry sibs rubbed elbows with top ranking politicians and movie stars, became highly unlikely cult heroes to some, and also inspired the 1990 film The Krays. There’s plenty of juicy raw material from which to draw, but Helgeland’s irreverent, wildly fictionalized approach to the material, based on John Pearson’s book The Profession of Violence: The Rise and Fall of the Kray Twins, tends to lean heavier on atmosphere and showy set-pieces than on forward momentum.

The plot gets set in motion by Reggie (Hardy), the zero cool businesslike club owner who falls hard for the sister of his chauffeur (Colin Morgan), a reportedly “fragile” 16-year old named Frances Shea (Emily Browning, gorgeous and terrific, though hardly a teen). Frances shares with Reggie her bigger aspirations than a life in the East End pushing a baby carriage and, as their relationship deepens, she urges Reggie to tread the straight and narrow. He swears that he will, lavishes gifts on her but, hey, but once a sociopath, always a sociopath. It’s poor Frances’ awkward, on-and-off voiceover (a nod to Sunset Boulevard) that gives us some entree into the twins’ twisted psyches — and, when necessary, she’s also burdened with delivering whole chunks of explanations of emotions and plot that the movie itself steamrolls right over.

Meanwhile, Reggie’s possessive, unapologetically gay brother Ronnie (Hardy again, although, in fact, it’s well documented that both Kray brothers were bisexual) is sidelined in a psychiatric ward for chronic violent behavior. He’s also the focus of a police investigation led by an uptight detective superintendent (Christopher Eccleston). Ronnie is a wild card, dangerously explosive and erratic. A shrink warns Reggie, “Your brother is violent and psychopathic. He’s off his rocker.” But the less obviously insane Reggie can’t bear to be without his symbiotic other half and threatens the right people to get Ronnie sprung from the institution. Not surprisingly, bloody pandemonium breaks loose.

Universal Pictures

Universal Pictures

Hardy could be accused of overplaying Ronnie as a cruel cartoony caricature, a rabid Neanderthal with pursed lips, a bulldog’s jaw, a raging libido, and a sweet tooth for his dotty mother’s cakes and teas. Still, he’s hair-raising and hilarious. But as Reggie, he’s much more grounded and lived-in, and when he accesses his innate old time Brando/James Cagney gangster movie wattage, he’s a genuine movie star. Helgeland even tosses him a few James Bond-style moments and Hardy aces them. It’s some of the best work Hardy’s done. Legend also boasts a top-flight supporting cast doing standout work – including David Thewlis, Paul Bettany, and Taron Egerton — but it’s Hardy’s show. And what a show he gives.