Targeted by a disabled former spy for the Crown who wrongly believes she is blackmailing his sister, Beatrice Lockwood offers her assistance in tracking down the real culprit and eventually falls for the spy only to find herself hunted by a mad scientist who would resurrect a dead lover.

"The author of the New York Times bestseller Garden of Lies returns to Victorian London in an all-new novel of deadly obsession. Calista Langley operates an exclusive "introduction" agency in Victorian London, catering to respectable ladies and gentlemen who find themselves alone in the world. But now, a dangerously obsessed individual has begun sending her trinkets and gifts suitable only for those in deepest mourning--a black mirror, a funeral wreath,...