The old ones go first. Disappeared at night by policemen with jaguars. They’re found in the drained aquarium, lying very still.

In his follow up to the hugely acclaimed La Merde (reviewed 2012), Italian writer Cristian Ceresoli creates a world where the dog is red and God is a well-endowed nude with tattoos; where ambition is everything and human skin is traded. Our two unreliable narrators are a brother and sister; Kerfuffle, nicknamed Bafu (Stefano Cenci) and his sister Ado (Silvia Gallerano.) Pubescent 13-year-olds eager for adventures, they are narrating their life story. Whether we trust them or not is up to us.

It takes a moment to adjust your ears to the Italian accents, but once aboard, you’re off on a torrent of words, a journey that flows and eddies through light and dark until you wash up an hour later, beached and bruised. No safe harbour here.

Bafu lives for football and Adu for dance; dad is harsh and ambitious for them both, ‘we are his lasting hope, my sister and I’. Mum likes a drink and a good time. The family unit struggles to keep itself together as society falls apart and puberty adds complications: willy size is important on the football team. Grandpa is missing. A picture builds with hints of a police state and ethnic cleansing, of brutal guards and sinister buildings peopled with corpses. But is the cat really blue, is mum naked under a transparent cagoule, is it even an aquarium? Memory is subjective and childhood full of imagination. We don’t know who to believe.

Cenci and Gallerano are wholly convincing as children and their playfully antagonistic relationship rings true. Dressed in maroon vests and navy pants (almost West Ham colours) they are mocking and punchy with each other, competitive but supportive. There is real sibling love between them as they strive to keep a grip on circumstances that change quickly and are beyond their, or their parents’, control.

Ceresoli’s rich, poetic text is so full of descriptive imagery that you could shut your eyes and see this unnamed city in technicolour, hear it sing. To do so would be to miss two performances of extraordinary force and sensitivity. Like kids, Cenci and Gallerano are rarely still, leaping and prowling over pieces of rostra in an unrestrained dance, full of fire. Clever lighting conjures up secret spaces and brings key moments into focus. Simon Boberg directs the movement with elegance and pace . A rhythmic, subtle soundtrack by Stefano Piro adds tension but never overwhelms.

So how, you may be asking, does all this relate the title, Happy Hour? Ceresoli has said that ‘In Happy Hour we are dealing with a condition of “dictatorship of happiness” and that the children see this coming. “Mom and dad are happy, because being happy is a must.”’

Whilst the words ‘happy hour’ are repeated at intervals, and there’s a horrifically vivid, physical realisation of it at the end, it’s not quite strong enough as a central theme. What we get most powerfully is a play about the rawness and vulnerability of childhood, showing how a city – ‘Paris! New York! Milan! Beijing!’ – any city, can slide stealthily into chaos.

A play that surprises like surrealism and sounds like a symphony, angry, passionate and compelling.