Trelkovsky is a character from the film "The Tenant," directed by Roman Polanski. The story follows Trelkovsky, a shy and introverted man who moves into a Paris apartment previously occupied by a woman who died under mysterious circumstances. As he settles in, he becomes increasingly paranoid and feels that his neighbors are conspiring against him. As Trelkovsky's mental state deteriorates, he begins to adopt the identity of the deceased tenant, leading to a disturbing exploration of identity and isolation. The film delves into themes of alienation and the impact of environment on mental health, showcasing Polanski's signature psychological tension.