Filmed in Britain, Fellow Traveller is set during the waning days of Hollywood's Communist witchhunt. The film begins with the suicide of unfriendly movie star Hart Bochner; we then briefly flash back to the friendship between Bochner and his close friend, blacklisted writer Ron Silver.
Working pseudonymously in England, Silver seeks out the late Bochner's girl friend Imogen Stubbs, who has not renounced her leftist views. He has an affair with Imogen, and through her regains his commitment to his own political preferences.
Incidentally, the TV series for which Silver writes in Fellow Traveller is the popular The Adventures of Robin Hood, which actually did hire blacklistees in the mid-1950s.