London, 1888. Veronica Speedwell has made a name for herself chasing rare butterflies and stranger mysteries. Her partner in both is Stoker, a naturalist with a guarded past of his own.
Stoker's former expedition partner, John de Morgan, disappears from a Dover hotel room. He takes with him a jeweled diadem lifted from an Egyptian princess's tomb. The dig he abandoned has been dogged by accidents since it began. Whispers now claim the princess's curse has followed the diadem to England, and that a figure got up as Anubis stalks the city's streets at night.
Veronica treats the curse as theater, but the theft is real. So is the danger closing in on the expedition's survivors. What she finds is an old, unsavory tie between Stoker and the missing man, one that could unravel his reputation along with the truth about the diadem. She sets out to clear him. The suspects are a household of people who each have reason to want de Morgan gone.
The third Veronica Speedwell mystery pairs a locked room disappearance with an Egyptology plot. It reads well enough as a standalone. Readers who arrive from the earlier books will feel the weight of what Veronica and Stoker already carry between them.