Christmas, 1669. In the grip of the coldest winter for years, the River Thames is frozen from bank to bank and London celebrates with a traditional frost fair held on its broad back. Revellers come from far and wide to enjoy the spectacle: an ox is roasted, booths set up and entertainers employed to amuse the crowds enjoying the holiday atmosphere. <p/>Among the throng is ambitious young architect Christopher Redmayne, escorting the daughter of one of his clients with whom he hopes to further a romantic attachment. By chance they meet Christopher's good friend, Constable Jonathan Bale. When a child slips on thin ice the pair make a chilling discovery of a frozen naked corpse embedded in the ice.
