The Sudbury School Murders. Captain Lacey Regency Mysteries, #4

In the spring of 1817, I take a post as a secretary at the Sudbury School in Berkshire, a school for sons of the wealthiest merchants and bankers in England. However, as soon as I arrive, I discover that I've been hired for more than letter-writing skills. A series of disturbing pranks have kept the school in an uproar, and the headmaster expects me, to my dismay, to discover the identity of the prankster.
The problems intensify when a groom of the school's stables turns up dead in a lock of the nearby canal. As I work to discover what happened, I become drawn into the secrets of Marianne Simmons, the actress who'd lived upstairs from me in my tiny lodgings in London. Marianne swears me to silence, which puts a new strain on my friendship with Grenville. Meanwhile the intrigue surrounding the murder becomes as murky as the waters of the canal itself and plunges me and everyone I care for into deadly danger.