Collateral Damage

Collateral Damage is the twelfth episode of the ninth season of Stargate SG-1.

Plot
SG-1 establishes diplomatic relations with the Galarans, a moderately advanced human civilization that has enjoyed generations of peace under the Asgard Protected Planets Treaty. SG-1 discovers that the scientists of this world have recently built a device based on Goa'uld technology that can implant the memories of one person into another, remove memories, or even create new ones. They believe that the device could revolutionize their society with the knowledge of one generation quickly and easily passed on to the next, reducing the time and cost of educating a new generation of people.

Cameron Mitchell experiences the astonishing technology first-hand as a demonstration to the rest of SG-1. Mitchell strikes up a relationship with the head of the project, Dr. Reya Varrick. This platonic relationship quickly becomes a romantic one when Cameron consoles her after she discovers that the military plans on taking over the project. She invites him back to her apartment, where they share a drink and she comes on to him. When he wakes up in the morning, he finds himself in her apartment with blood on his hands and apparently remembers committing the murder.

The authorities arrest Mitchell, but he's pardoned by Varta, the High Emissary of the world, in an attempt to maintain negotiations between this world and Earth. Mitchell turns down the pardon and pushes for an investigation, believing that his memory of the murder is false and probably implanted in his mind with the memory device. This puts him in a dangerous position, as the penalty for murder, if convicted, would be death. With the aid of two scientists involved in the project, Amuro and Marell, Cameron is hooked up to the machine and is prepared to scan the suspect memory to determine if it's false. Before they begin, the scientists use two important real memories from Mitchell's past to establish a baseline. It is here that a part of his life is revealed. It's revealed that his dad was a test pilot for the Air Force until he lost both legs in an accident, and we also learn that he was ten when the first space shuttle was launched (STS-1 April 12, 1981 - April 14, 1981). After enduring the process of watching the memory of the murder repeatedly, it's discovered that the memory looks real. This angers Marell, who is revealed to be married but separated from Reya.

Teal'c and Daniel, meanwhile, are searching for clues in Dr. Varrick's records, but are frustrated that parts of it are censored. When Varta reveals the results of the memory scans and suggests the possibility of sending Mitchell back to Earth and covering up the murder, Daniel responds by threatening to prevent an alliance between Earth and Varta's world.

Back in the lab, Mitchell undergoes the memory scan again, this time using a memory with similar emotional content to the murder so as to compare the results. They use a memory of him using a F-16 to bomb targets which eventually turn out to be innocent refugees. This time, they discover an inaccuracy in the memory, proving that Mitchell is indeed innocent. At Mitchell's insistence, Marell scans deeper to try and uncover the identity of the real killer. In the memory, Cameron sees his reflection in a mirror, but the face is blurry. Going even deeper, the face is soon revealed - Marell's! Disconnecting from the memory device, Mitchell reveals his discovery, but he, Sam, and Amuro find that Marell erased his memory of killing Reya after implanting it in Cameron's mind.

Later, the memory is removed from Mitchell's mind and the team discovers that Marell's memory has been altered and he now believes Reya was killed in an accident.

At the SGC, Landry talks with Mitchell who knows about his past because he has read Mitchell's service record.

The episode is dedicated to the memory of Jeff Upton who was a gaffer on the series. 

In other languages
German: Kollateral-Schaden