This is a very strange, grown-up play for children. In the fictional city of Schwartzgarten, little pyjama-clad Conrad imagines a pet tiger. His father, a child psychologist, disguises himself as a mysterious stranger, Mister Holgado, in order to cure his son and save his marriage.

Odd, bizarre, like a mixture of Roald Dahl and Franz Kafka, Christopher William Hill’s play describes a territory between bed-time story and waking nightmare where children should be observed closely, like beetles under a microscope, and adults treated with maximum suspicion.

What’s missing on all sides is love, and this only follows after much scariness and maltreatment and a rather over-extended chase sequence in which Conrad locks horns with Mister Holgado in a violent contest that can only be described as friendly Freudian.

Although the eight or nine-year-old children I sat with were visibly stirred and shaken, I yearned for a more detailed and populated environment on Marshall Podolski Street in Matthew Lenton’s extremely controlled production, despite accounts of what’s going on at the zoo with the penguins and tigers.

Still, this is one of the most striking children’s plays I’ve seen in a while, exceptionally well designed and performed. Kai Fischer’s four-door set creates good space on the fan-shaped stage for Father’s study, Conrad’s bedroom and the dangerous kitchen.

Conrad is unfussily played by Daniel Naddafy, while Sandy Grierson inhabits three fearsome characters with a fine Dickensian relish, and the brilliant, Lecoq-trained Cath Whitefield makes of Mother a gibbering, hilarious wreck of accommodating tics, gurgles and anxieties, forcing you to realise that when a child’s got problems they’re nothing compared to those of the parents.