Junkhearts

Middle-aged Frank (Eddie Marsan) is a broken man, and utterly alone. Still traumatised from his experiences serving in Northern Ireland, and long estranged from his wife and daughter, he leads a dazed existence in his elevated council flat in London's East End, stumbling out only to replenish his supply of cigarettes and whiskey miniatures. Lynette (Candese Reid) is similarly alone – a mouthy 17-year-old Nottingham runaway sleeping rough on the streets below.

Though their first contact is awkward and aggressive, these two lost souls are soon drawn into each other's orbit, and as Lynette moves into Frank's flat, the father-daughter bond that forms between them enables both to start rebuilding their lives. With Lynette, however, comes her boyfriend Danny (Tom Sturridge), an opportunistic and exploitative dealer looking for a new crack den and, as a native of Belfast, embodying all of Frank's worst nightmares – and before things can get better they are clearly going to get a lot, lot worse. Meanwhile, as upper-middle-class business woman Christina (Romola Garai) struggles to balance the accounts of single motherhood, adultery and drug use, a piece of unexpected bad news brings home her own sense of isolation.

Indeed, while the different characters' storylines in Junkhearts will all eventually converge in a not entirely unpredictable manner, loneliness is the thematic glue that binds them together, transcending class to drive everyone to the kind of self-destructive displacement afforded by addiction. Tinge Krishnan, whose 2001 short Shadowscan won a BAFTA, suffered Post Traumatic Stress Disorder after working as a volunteer doctor in the aftermath of the 2004 tsunami, and brings that experience to her feature debut, depicting Frank's day-to-day life in a woozy blur of half-focused hand-held close-ups and hallucinatory sound design.

It is a striking audiovisual style which rescues this production from many of the more hackneyed tropes of British social realism and urban grit – and Simon Frank's screenplay earns its contrived (but too open to be truly contrived) ending by getting us there through the unapologetically bleak terrain of betrayal and breakdown. Frank, in particular, is put through the emotional wringer in this film, with Marsan expertly incarnating each and every scar of his character's delicate psyche, in a sort of flipside to his role in Tyrannosaur - although the lesser known Reid also holds her own.

Perhaps most extraordinarily of all, while Frank may, like the title character of Luc Besson's Léon (1994), be a killer who trains a much younger female ward in the art of fighting, neither of them actually comes to blows, thus giving the lie to the old cliché that a loaded gun seen in a movie must eventually go off. On the contrary, here cycles of violence and other dependencies have to be left behind, and debts are paid with old money rather than given new currency.