Young reporter-in-training Kate and her mouse-accomplice Rupert are on board a train, to visit Kate's mum in the Arctic.

But as soon as the train departs, mysterious things start happening.

A packet of ginger nuts goes missing . . .
A collection of gymnastics trophies are stolen . . .
And some ancient scrolls disappear . . .

Fellow passenger Madame Maude seems the most likely culprit, until a surprising - and delicious - twist turns the whole investigation on i ...