When a school caretaker mysteriously disappears, leaving behind a small pile of sand, a student is drawn into an extraordinary adventure.

Ten-year-old Max feels like an outsider at St Goliath’s. He is deaf, and while this doesn’t need to be a problem, the unlikable head ensures that it is, singling him out with a special seat in assembly and showing him off like an exhibit to visitors. He’s also clearly neglected to ensure Max’s peers understand how to foster normal, meaningful relationships with someone who happens to be deaf.

Then Max makes a miraculous discovery – a tiny civilisation in the pile of sand on the caretaker’s floor. It’s a miniature world at war: three bickering tribes, nonsensically segregated according to hair colour. Can Max find his missing friend, communicate with the tribes and bring about peace?

Alongside the adventure, and with a light hand, Montgomery successfully touches on challenges such as coping with buzzing hearing aids, lazy assumptions about deafness, and people’s inept attempts to communicate better by shouting.

The plot is delightfully daft and complemented by many subtle social comments about inequality, the abuse of power and the futility of war.