A mentally disturbed artist serving a 50-year sentence for double murder who channels his experiences into art. He paints an abstract nude portrait of prison guard Simone, sparking his initial recognition. Later, he secretly creates a massive series of frescoes directly on the concrete walls of the prison hall. His work eventually draws art dealers and mobsters to the prison, leading to a standoff where the walls are airlifted to a private museum. He is released on probation after stopping a riot and maintains a long-distance correspondence with Simone.
Simone serves as the primary emotional motivation and artistic muse for Rosenthaler during his incarceration.
Both writers contribute separate, distinct stories to the final edition of The French Dispatch.