The husband of Monk's former assistant, Sharona, has been arrested for murder. Now back in San Francisco, she's ready to reclaim her place in Monk's life — much to the chagrin of his current assistant, Natalie. While Monk tries to maintain a delicate balance between the two women, he discovers a few unsettling snags in the case against Sharona's husband, and may be up against a killer who not only understands him, but is one step ahead.