In the spring of 1812, Piers Withan is dragged from his beloved Oxford to be the new Viscount Petteril. Burdened by responsibilities he doesn't want and the remnants of a family who don't want him, he is saved from an irredeemable mistake by Ape, the small thief burgling his house.

When the family heirloom known as the Petteril Necklace is found to be missing, Piers seeks out his burglar to get it back. However, their search leads them to Piers's own family - entitled, resentful and largely indebted. Only, which one of them is the thief?

As he uncovers the truth, Piers begins to find his feet and his old joy in life, not least in his burgeoning friendship with Ape, whose past is a mystery of its own.