Solaris

Psychologist Kris Kelvin arrives at a research station hovering over Solaris, a planet covered by a single ocean that may itself be a mind. He finds the crew unravelling — and is soon confronted with a visitor who cannot exist: his wife, dead for years, rebuilt from his own memory. Lem's masterpiece turns first contact inside out: the ocean studies the humans, and true communication may be impossible. One of the most translated works of European science fiction.