On demand: "Balloon"

Balloon, co-written and directed by the marvellously named comedian-turned-filmmaker Michael Bully Herbig, finds the German film industry once again reckoning with the country's not so distant past, and more urgently than the film's kooky-airy premise would suggest. Its first dramatic coup is to pitch us headlong into what feel like pivotal, if not indeed climactic events: a defection attempt planned by a family of four from Pößneck, East Germany in 1979, using as their unlikely escape vehicle a homemade hot air balloon. There's very little exposition, save to determine that anyone seen looking even remotely shifty by, near or over the border was typically shot on sight; Herbig touches on the GDR's widespread monitoring and surveillance program (already amply covered in The Lives of Others), but is keener to flag up the issue that a giant balloon illuminated from within might be no more than a moving target in the night sky, and its passengers sitting ducks in a basket. The journey time from Pößneck to safety in the FRG was only just shy of an hour, and for a while, you might wonder whether the film is going to play these events out in fraught real time. Here, though, Balloon stages its another coup: having what feels like a one-shot, make-or-break getaway attempt fail spectacularly, thus allowing official suspicion to redouble as our dishevelled heroes regather themselves and their belongings and rally for a second pass. To paraphrase an English song of a far older vintage, there are some ups, some downs, and - in between those - some understandably nervy flying around.

The downtime allows Herbig to feel out the attitudes of an era. The Army official poking through the (abandoned) wreckage of that first balloon is a grizzled functionary of the State (Deutschfilm veteran Thomas Kretschmann), but also a pragmatist who reckons the so-called "riff-raff" ought to be allowed to leave without undue penalty if they so desire. A neighbour who has the look of a conformist stooge wants his TV tuned to a Western signal so he can watch Charlie's Angels. We hear a joke East Germans were telling one another about Erich Honeker, albeit not in public. Yet the abiding atmosphere is tense, coiled rather than cosy; there's none of that latent cuddliness that ensured Goodbye, Lenin! crossed international borders, because the stakes appear vertiginous from the off. (An opening title card suggests some 400-plus prospective defectors were shot on sight under the GDR's border policy.) At every turn - on a shopping trip, and again during a few days away in East Berlin - the family threaten to give themselves away; there's no easy way out of this place, and the net is rapidly closing in. Though the expected period signifiers are all in place (wide collars, Bakelite phones, longwave radio sets), there's nothing unduly flashy about the filmmaking. Instead, Herbig proceeds smartly and efficiently from a strong script, not bullying exactly, but ruthless in the way he splits up teenage lovers and leaves even kindergartners liable as potential informants. (Those were the days.) Pro tip: don't read up on how the second attempt turned out, and the final half-hour will play as excruciatingly tense. Either way, Balloon is finally what any escape from the East Germany of the late 1970s had to be: expertly strategised and marshalled.

Balloon is currently streaming on the BBC iPlayer.