When Boy wakes up it's the coldest day of the year - his breath puffs like a dragon, and there's ice in his cup of water. Boy and Grandad are on a mission to get warm. They put on their hats, jumpers, scarves and coats, and set off down into the cellar to discover why they're so cold. And so begins a spectacular nautical adventure around the world.

The second title in Sam Usher's new quartet, where Boy and Grandad put their skills to the test to mend, reuse and recycle.