January 1941. When Detective Inspector John Jago is called to a terraced house in London's Bloomsbury district, he finds the body of a woman who has been attacked and left to die - her crime, it seems, being kindness to strangers. Rosemary Webster had taken in victims of the devastating Blitz and refugees from wartorn Europe and given them refuge in her own home, but now she's a victim too - of cold-blooded murder. Jago is on the trail of a killer, pursuing them across Bloomsbury's leafy squares and into the distinguished environs of University College London, uncovering a tangle of damaged hearts and minds as he goes. There may have been envy, resentment, even outright hostility. But who would want to strike down an angel of mercy in her own home?