Peter Grant has been doing some research on an old case in the annexe of the Folly's library. He has discovered that his mentor, Thomas Nightingale, befriended a man named Angus Strallen during the Second World War after Strallen witnessed Nightingale fell an enemy aircraft with a wave of his hand. The pair were reunited in October 1957 as they attempted to track down a dangerous murderer who targeted women: one Professor Uwe Fischer.
The ex-Luftwaffe-pilot-turned-scientist remained one step ahead of Nightingale and Strallen at every turn, seemingly surrounded by powerful allies. With the detectives hot on his trail after his attempted murder of Asterid Bivalacqua, Fischer decided to leave London and head back to Cumbria. But returning to his day job at Windscale, an atomic reactor plant in the North West, could prove to be even more deadly for the unsuspecting people of Britain…
