The poet Roald Mandelstam lived in postwar Leningrad. He was seriously ill from childhood, rarely left his house, and knew his life would be short. His visitors included the composer Isaac Schwartz and a painters that would come to be known as the "Arafiev circle," a group of independent artists working outside of official oversight. After 50 years, a fresco was discovered under the wallpaper in his communal apartment...