Philippe Sands, a barrister and Professor of International Law at University College London, brings together in this multi-faceted book the perpetrators of the worst crime yet devised by man and pits them against two lawyers who were instrumental in providing the legal underpinning for their conviction. This is no dry legal tome: the story Sands tells is intensely moving and a personal family memoir about his maternal grandfather, Leon Buchholz, and his wife, Rita.

The story centres around Lviv, a city which changed hands eight times between 1914 and 1945. When it was a part of the Austro-Hungarian Empire, it was known as Lemberg. After 1918 it became part of Poland and was renamed Lwów. Later, when conquered by the Soviets, it was known as Lvov. During World War II Germans occupied the city. Finally, after 1945 it became part of Ukraine and reverted to Lviv.

Lviv was where some of the Sandses were taken and never heard of again. Hersch Lauterpacht and Raphael Lemkin also studied law there. Lauterpacht moved to Vienna to further his studies, and then to England. At Cambridge he became a distinguished international lawyer; later a judge of the International Court of Justice. It would not be an exaggeration to say that Lauterpacht effectively wrote modern international law. Lauterpacht's son, Sir Eli, who is also a distinguished international lawyer, taught Sands at Cambridge.