An unlikely con man wagers wife, wealth, and sanity in pursuit of one of art's elusive old masters.

Martin Clay, an easily distracted philosopher, and his scrupulous art-historian wife are invited to dinner by a boorish local landowner to assess the value of three dusty paintings moldering in the freezing breakfast room. But blocking the soot from the chimney is nothing less, Martin believes, than one of the world's lost treasures, camouflaged by misattribution and the grime of centuries. Thus begins a wild trail of lies and concealments, soaring hopes and sudden panics, as Martin embarks on an obsessive quest to prove his hunch, separate the painting from its owner, and resolve one of the great mysteries of European art.