Capri Sanzio knows that when you give serial killer walking tours for a living, unexpected situations are more common than San Francisco's famous fog. So, when one of her guests claims to see a woman being attacked during a tour, Capri remains unphased. The police search the apartment in question and find no evidence of anything amiss, so they chalk it up to a false report from a true crime fanatic looking to be a part of a case. And Capri thinks they might be right, since lately her tours have been attracting even more obsessives than usual--as it turns out, finding the actual serial killer who committed the "Overkill Bill" murders didn't stop the constant questions about her grandfather's supposed crimes, it only intensified them.

But Capri would never forgive herself if someone is in trouble and she walks away. Plus, something about the whole situation has every one of Capri's investigative journalist instincts going haywire--why would someone lie about seeing an attack? So Capri starts to dig, and when her questions lead to a body, she finds herself at the center of another murder investigation.