The Palace Guard

A museum robbery leaves a guard dead, and two Boston sleuths investigate: “If this is your first meeting with Sarah Kelling, oh how I envy you” (Margaret Maron).
  It’s only been a few months since Sarah Kelling’s elderly husband passed away, and she’s struggling to adapt to life as a penniless young widow. To make ends meet, she converts her stately Boston home into a boardinghouse, a decision that brings something even better than money: the company of art-fraud investigator Max Bittersohn. The budding couple is standing on a balcony, recovering from a second-rate concert at a third-rate museum, when something plummets past them. The museum has been robbed, and a guard has fallen to his death. Dozens of priceless paintings have been stolen and replaced with forgeries, and recovering these masterworks will mean tearing the lid off the quiet life of the Boston upper crust. But it’s a chance Sarah and Max must take, lest they join the guard on his long trip down.