January, 1941. Amid the devastation of the Blitz, Detective Inspector John Jago is called to Bloomsbury where the body of a woman has been found. Rosemary Webster was known for her generosity, offering refuge to bombing victims and refugees from war-torn Europe. Now she is the victim of a brutal, cold-blooded murder. As Jago traces her final days through Bloomsbury's leafy squares and into the halls of University College London, he uncovers a web of strained loyalties, envy and buried resentments. Many owed Rosemary their safety - but someone wanted her silenced. In a city already under siege, Jago must discover who would kill an angel of mercy in her own home.