Death Was the Other Woman (2009) is a mystery novel by Linda L. Richards set in the 1930s, as Prohibition and the Great Depression rack the nation. Young and bright protagonist Kitty Pangborn works as the secretary and assistant to the drunk, but talented, private eye Dex Theroux, hoping to make enough of a living for herself to get by in hard times. Though the pair work primarily on the streets of Los Angeles, they find themselves driving up the California coast when the beautiful and wealthy Rita Heppelwaite asks them to tail her cheating boyfriend, the businessman Harrison Dempsey. However, Dempsey is up to more than just two-timing, and soon Kitty finds herself in danger as she drives up and down the Golden State trying to uncover the name of a dead man they find in a bathtub.
As the novel opens, Kitty Pangborn and her boss Dex work through the Depression in crime-ridden Los Angeles. In this era, knowing that one can either make money committing a crime or solving it, Kitty chose to become a secretary for Dex Theroux in the hopes of securing a regular salary for herself. Dex is a raging drunk and always has a bottle of whiskey with him, but underneath it, he is a smart detective and a reliable man.
At the beginning of the novel, Kitty and Dex receive a visit from Rita Heppelwaite, the mistress of the well-known businessman Harrison Dempsey. Dempsey is already married, but Rita suspects him of stepping out on her with another woman—triple-timing everyone. Rita wants Kitty and Dex to follow Dempsey to figure out what he is up to, leaving Kitty wondering what will come next—Dempsey is a rich man, and also one of the shadiest businessmen in California. Kitty knows that whatever they find trailing Dempsey, it won't be anything good.
At first, Dex agrees to take on the case, leaving Kitty in the office. But Kitty, knowing that Dex will be drunk as a skunk the whole time, doesn't trust him to find his own way back home, never mind keep himself on the tail of a gangster. So, she insists on accompanying him with the hope of protecting her own salary.
Dex and Kitty embark on their mission to find Dempsey, who has recently disappeared from the scene. They rent a car and drive around the city, walking into nightclubs, speakeasies, and casinos on the hunt for their missing man. Their clues take them up and down the California coast, and introduce them to a number of odd characters, including Mus, Dempsey's old army buddy and “fixer”; Lilla Dempsey, the wife of their target; a gambler named Hopscotch; and Rita Mayhew, whom Kitty suspects is an important figure hiding in plain sight.
A number of clues lead the reader, and Kitty in Dex, in all directions—the connection to Kitty's former housekeeper and current landlord, who played the stock market during the crash and took over Kitty's family's estate, and a pair of steamship tickets come into play in mysterious ways. There is also the quandary of an unidentified dead man the pair finds in a bathtub in a hotel, whose body disappears and reappears in a very strange place. As the mystery unfolds, Kitty soon discovers that this is about more than just a love affair—her very life may be in danger.