Now part of the Russian Baltic enclave of Kaliningrad, the former Prussian and German port of K?nigsberg has always been a somewhat sleepy place, doomed to be famous for having once been the residence of Immanuel Kant. But in the late 1830s, just for a short while, it became famous for all the wrong reasons. Christopher Clark’s book is the result of many years of fascination with this strange case. Sensational accusations were bandied about, implying that beneath the town’s somnolent surface there were dark erotic currents and wrenching betrayals of trust. For the Prussian authorities this was just the sort of moral collapse they feared most. In the aftermath of the Revolutionary and Napoleonic Wars, which had unsettled a generation, every lapse could be seen as the harbinger of new storms.