In this novella, Annie and Nate Dawson, the amateur sleuths from M. Louisa Locke's cozy Victorian San Francisco Mystery series, are visiting Nate's family at their ranch near San Jose, California. What was supposed to be a pleasant romantic interlude for the two of them, plus a chance for Annie to get to know Nate's family better, turns serious when a crime is uncovered. And, as in Locke's short stories from this series, Annie gets help in resolving the crisis from a very unexpected quarter. Violet Vanquishes a Villain comes right after Deadly Proof, the fourth book in the series, although it can certainly be read as a stand-alone story.