Before the events of Moon: The real Sam Bell hired Tess as an intern. After her internship ended, he asked her out, they began a relationship and eventually married. Their marriage ran into difficulties and they separated for six months, then got back together. Sam trained as an astronaut and went to the Moon to work for Lunar Industries, extracting helium-3 from the soil for energy production. While Sam was on the Moon, Tess sent him video messages and showed him his daughter, Eve Bell, who was born around the time Sam left Earth. After three years, Sam returns to Earth. Lunar Industries had decided that it is too expensive to train and ferry workers to and from the Moon: instead, they create clones of Sam (apparently about a hundred), implant them with the real Sam's memories and keep them cryogenically frozen. The first clone (call him Sam-2) is sent into the main part of the base and is revived by the robot GERTY, who tells him that he had an accident, giving him an explanation of his lack of specific short term memories. Sam-2 serves his three-year "contract". During this time, he is told that solar activity has damaged the communication satellite, making live communication with Tess impossible. In reality, she is continuing her life with the real Sam, and Lunar Industries just show Sam-2 videos of her original messages (after editing out any information that might give away precise time references), while all the videos Sam-2 sends her go nowhere. At the end of the three years, his health deteriorating, Sam-2 enters a pod, where he is told by a video he will be cryogenically frozen for his return to Earth. A video of a Lunar Industries engineer explains this to him, ending with "goodbye". He is then cryogenically frozen, and an instant later, incinerated by pod. Eve is now 6 years old. Sam-3 is awakened, serves his term and goes through relatively the same life that Sam-2 had; being incinerated at the end of three years. Eve is now 9. Sam-4 then goes through the same process, serving his term and being incinerated. Eve is now 12. Tess dies at some point in Eve's childhood. Sam-5 (the protagonist of Moon) then begins his term.
Events during Moon: As Sam's contract nears its end, he begins to suffer from hallucinations, one of which causes him to crash the moon buggy into a harvester. Lunar Industries assume him to be dead, and thaw out Sam-6, who rescues Sam-5 from the buggy. Although they suspect it, GERTY reveals that both are clones, and they discover that Lunar Industries are blocking their radio signals by surrounding them with antennas. Sam-5 drives out of range of the signal blocker and calls Sam Bell's home. Eve (now 15) answers, telling him that Tess is dead. Sam-5, overcome with emotions, begins asking about her, causing Eve to call for her Dad (revealing that the real Sam Bell is alive). With only a few hours before the "rescue" team arrives, the Sams realize that if they are discovered together, they will both be killed. Sam-6 plans to launch Sam-5 back to Earth hidden in the helium-3 delivery vessel, and thaws out a new clone, Sam-7, to kill and take Sam-5's place in the rover. But Sam5 realizes that he is already dying, and insists that Sam-6 be the one to escape. Sam-5 returns to the rover to die. After reprogramming a helium harvester to crash into one of the jammers and erasing GERTY's memory so there is no evidence that GERTY helped him, Sam-6 launches his escape, which Sam-5 sees in his final moments. Right as Sam-6 escapes, Sam-5 dies in the rover, GERTY reboots and Sam-7 finally awakens in the infirmary, the rescue team arrives, presumably finding Sam-7 and GERTY in a typical routine. The rescue team then go to the rover and find Sam-5 dead as they suspect, having no idea that Sam-6 escaped. The harvester is then shown destroying one of the antennas, resulting in the base computer reporting that a live up-link has been established (allowing the presently-clueless Sam-7 a direct link to Earth). As the vehicle Sam-6 is in is shown entering Earth's atmosphere, voiceovers from future news reports hint at worldwide media attention of the incident and legal hearings to which Sam-6 gives evidence.