In The Bughouse Affair, the first of a new series of lighthearted historical mysteries set in 1890s San Francisco, former Pinkerton operative Sabina Carpenter and her detective partner, ex-Secret Service agent John Quincannon, undertake what initially appear to be two unrelated investigations. The two cases eventually connect in surprising fashion, but not before two murders and assorted other felonies complicate matters even further. And not before the two sleuths are hindered, assisted, and exasperated by the bughouse Sherlock Holmes.