What does Homer Kelly (an ex-detective, now a professor) know about art? Nothing at all. And therefore, when Titus Moon, the new young director of the Isabella Stewart Gardner Museum, invites Homer to a trustee's meeting, and Homer realizes he is going to be expected to ward off the disaster threatening that distinguished Boston landmark, "Mrs. Jack Gardner's palace," Homer is worried.

The great and famous collection assembled by Mrs. Gardner around the turn of the century includes Raphaels, Rembrandts, Botticellis, a Vermeer, a Rubens and one of the most famous Renaissance paintings in the United States, Titian's magnificent The Rape of Europa. Homer, as he listens to the trustees, realizes why the safety of these works of art is in jeopardy. Mrs. Gardner's will stipulates that everything in the museum must stay exactly as it has always been, or the collection will be dismantled.

Homer and security chief Charlie Tibby struggle to bring things to rights, with the help of Titus Moon and his new assistants Polly Swallow and Aurora O'Doyle. And, as their efforts fail, as the problems accelerate, the trustees bring to a vote again and again an apocalyptic question: "Should the museum be dismantled and its contents sold at auction, in accordance with the stringent terms of Mrs. Gardner's will?"

In the end, there is murder, anger, and anguish until matters are brought to a grand finale with a wild jostling that tumbles events into a spectacular new shape.