Enola Holmes, Sherlock Holmes's younger sister and self-declared finder of lost persons and things, is determined to find her friend, Lacy Cecily, a confused young Baronet's daughter on the run from her father's devious schemes.

Enola Holmes, now independent and pursuing her profession as a scientific perditorian, joins forces with her brother Sherlock to solve the mysterious disappearance of Wolcott Balestier, a friend of Rudyard Kipling, as they uncover the ruthless world of book publishing and seek to bring him back safely.