The Frozen River Thames gives up its secrets Christmas, 1669. In the grip of the coldest winter for years, the Thames is frozen from bank to bank and London celebrates with the traditional Frost Fair held on its broad back. Among the throng are Christopher Redmayne, an ambitious young architect, and his good friend, Constable Jonathan Bale. But the pair make a chilling discovery: the frozen corpse of a naked man embedded in the ice. Christopher is further drawn into the mystery when his own brother is accused of the murder. With his brother facing execution, the architect must risk all he holds dear, both professionally and personally, to uncover the truth.