Enola Holmes gets involved in another deadly mystery: this time the life of her beloved housekeeper and surrogate mother is at stake.

Enola Holmes doesn't get much from her family these days; his mother has disappeared and he has to hide from his favorite brother, Sherlock. It's no wonder that he considers his housewife, Mrs. Tupper, who is almost completely deaf and has serious challenges in the field of cooking, but has a golden heart, as a kind of surrogate mother.
But one day, to his horror, he comes home to find that Mrs. Tupper has been kidnapped. Who could have done this and why? And what does the confusing history of the Crimean War have to do with the legendary nurse Florence Nightingale?