This is a magical adventure story about an orphan called Measle who lives with his horrible guardian, Basil Tramplebone. Basil is a Wrathmonk - the worst kind of wizard - and when he finds Measle playing with his beloved train set he zaps him with an evil spell. Now Measle's only a few centimetres tall and trapped in the world of the train set. There's a hungry bat in the rafters waiting for nightfall to swoop down on Measle and there's an enormous cockroach after him, but Measle finds some friends in the train set and together they come up with a plan.