Herman Wallace may be the longest-serving prisoner in solitary confinement in the United States -- he's spent more than 40 years in a 6-by-9-foot cell in Louisiana. Imprisoned in 1967 for a robbery he admits, he was subsequently sentenced to life for a killing he vehemently denies. "Herman's House" is an account of the remarkable expression his struggle found in an unusual project proposed by artist Jackie Sumell. Imagining Wallace's "dream home" began as a game and became an interrogation of justice and punishment in America. The film takes us inside the duo's unlikely 12-year friendship, revealing the transformative power of art.