There are so many children involved in Carl Miller's new version of Erich Kästner's famous story that there may not be enough left in London to go and see the show. Emil's gang of new friends on the streets of pre-war Berlin come in three teams of fifty, and there are three children for each nominated role, too.
The charge was led on opening night by Ethan Hammer as Emil Tischbein, the boy from the small town of Neustadt who falls asleep on the train to Berlin and finds that his precious envelope of 140 marks (about £7, quite a big sum in 1929), which he is conveying to his grandmother in the city, has gone.
Although Emil is convinced that the slightly weird man in the carriage – in the book, Herr Grundeis, in the play, an Oliver Hardy-like Stuart McQuarrie as Mr Snow) – is the thief, it's the main source of tension in the book that Grundeis may be shifty and sinister for other reasons entirely.
Without that element of doubt and excitement, Bijan Sheibani's efficiently regimented production becomes a pictorial diversion and a somewhat repetitive assertion of child power ("Most parents and teachers are animal trainers") and Mr Snow a comic turn who wins a big laugh on complaining that life can be lonely in the financial sector.
Still, Sheibani and his designer Bunny Christie (with lighting by Lucy Carter) have created an extraordinary metropolis of dark streets and lampposts in a black and white Constructivist style, like a three-dimensional map, with a mobile grid of outlines and receding perspectives; after a rousing first act finale, the children dive into this dangerous vortex and pursue Snow from cafes and squares to the hotel, the bank and even a cabaret spot where Jacqui Dubois as Madame Mimi is crooning in the shady interior.
This is a long way from Emil's innocent provincial life where his widowed mother (Naomi Frederick) is making ends meet, just about, by being a hairdresser and chatting about the wicked world with her regular, possibly only, customer, Mrs Wirth (Tamzin Griffin). Emil has a guilty secret that drives him to make social reparation in his adventure: he's defaced a town statue for a laugh and therefore cannot seek any assistance from the police.
Emil's lieutenants include his tomboyish cousin, Pony the Hat (Izzy Lee on opening night), the bespectacled Professor (Daniel Walsh) and the quietly clever little Tuesday (Keeyan Hameed) who operates as a one-man nerve centre behind the scenes.
We all stand up for Emil as the great tribe of children rush through the city sewers and then through the Olivier stalls, and at that point you really do feel that a spirited unruliness has been transformed into an unstoppable force for justice and good will in the world.