In this historical history novella set in August of 1880, Annie and Nate Dawson's trip down the San Francisco peninsula to San Jose was supposed to be a pleasant romantic interlude and a chance for Annie to get to know Nate's family better. When the visit takes a serious turn, Annie races to expose a criminal who could ruin a young man's life, getting help from an unexpected quarter.
The events in Violet Vanquishes a Villain come right after Deadly Proof, the fourth book in Locke's USA Today bestselling cozy Victorian San Francisco mystery series, and before Pilfered Promises.