The third in the series of The Back Bay Investigation, Death Comes to Lake Como takes place a few years after the events of Mystery of Moutai and The Fatal Sin of Love. It opens with Fang Chen and his new bride corresponding with their friend, Ann Lee, while on vacation in Italy. Things quickly turn sinister when a nurse for a wealthy American tourist and a retired cook are murdered.
A teenager returns home from school to find a gruesome scene: the apartment he shares with his mother in Boston's Chinatown has been ransacked, and she is dead. There is a bottle of Moutai, the most exotic and expensive Chinese liquor, left at the scene and traces of rat poison in one of the two shot glasses on the kitchen counter. This was evidently a homicide, but who could possibly be the killer?
In Beacon Hill, one of the most desirable neighborhoods in Boston, a wealthy widow dies in her sleep, while in Cambridge, where academia meets high tech, a dog is slaughtered. One death has seemingly no bearing on the other until the death in a remote Chinese village is announced.