Corazón y Hueso is a subterranean story with its own mystique, harbouring its losers, its prison universe with its tattooed inmates, and characters with map-streaked hands who speak lunfardo, the slang of Buenos Aires with a secret vocabulary invented to defy the prison staff. When these men whistle a tune or start the first steps of a dance – tango, folk, or milonga (what does it matter?) –  it’s called canyengue (rough and ready, from the back streets), and looks more like a fight.