Matt Haig

Amelia Wishart was the first child ever to receive a Christmas present. It was her Christmas spirit that gave Santa the extra boost of magic he needed to make his first trip around the world. But now Amelia is in trouble. When her mother falls ill, she is sent to the workhouse to toil under cruel Mr. Creeper. Meanwhile, up at the North Pole, magic levels dip dangerously low as Christmas approaches, and Santa knows that something is gravely wrong....

"A independent mouse sets out on a quest to prove that cheese exists, and learns to appreciate other creatures along the way"--