Solaris tells the story of Kris Kelvin, a Russian Cosmonaut tasked with the job of finding out what happened to the three Cosmonauts inhabiting a space station above the mysterious planet Solaris. Once aboard the space station, Kris finds the space station in a surreal state of decay with one of the Cosmonauts having committed suicide and the other two in a serious state of mental unease. Not long after boarding the vessel, Kris himself starts becoming mentally unstable as visions of his long-deceased wife begin materialising before him. Like much of Andrei Tarkovsky's work, the film has a lot of religious and metaphysical overtones. However, the film also tangentially covers many topics salient to existentialism. Specifically though, the reason Kris Kelvin appears on this list, once again, comes down to choice. As the film progresses, it becomes apparent to the scientists that the planet Solaris is not merely a floating rock in space, but a sentient being that is attempting to communicate with them through hallucinations. Towards the film's finale, Kris is given a choice of returning back to earth or staying with Solaris. Kris Kelvin's choice is one that many undoubtedly would categorise as "false' or "illusionary", but it is Kris's rejection of an absolute understanding of reality that gives him the freedom to define himself as he sees fit. And for this, he is inarguably an existentialist.