Grandfather buys a toy Ark for Imogen, to be fetched the next day.

So Imogen sticks a note: 'this probably belongs to Imogen', inside.

In the night, a fire destroys the shop; and the flood from the sprinklers sweeps the Ark down the drain on a rocking ride around the world and, finally, back to the rebuilt shop.

Imogen, of course, can show the shopkeeper that the Ark is really hers, because there is the sticky paper saying so. And anyway, she knows what's been happening to Noah and his family on their extraordinary journey because she's been thinking about them all the time - and even talking to them on her bright red telephone.