Sergei Vallarin

Major Vallarin was a member of the first official Russian SGC team under the command of Colonel Zukhov. He and his team were sent to the planet P2X-338 after SG-1 discovered it to be a location a secret Russian team had been sent to by Russian Army Intelligence.

The two groups arrived at the entrance to a ziggurat which they believed had been used by the Goa'uld masquerading as the Babylonian god Marduk. As soon as they entered the ziggurat, however, everything went wrong. Zukhov set off a booby trap when he found Marduk's sarcophagus which locked the entrance to the ziggurat, the entrance crushing Lieutenant Marchenko in the process. Soon after this Lt. Tolinev, another of Vallatin's team, was attacked by a strange creature which was housing Marduk's symbiote, poisoning her and sending her into shock.

Jack O'Neill of SG-1 paired off members of each team, keeping Vallarin with Daniel Jackson so that the creature would not be able to attack any others. Vallarin, disobeying the order to stay with Daniel, left his post when he heard a strange noise down a hallway they were next to. The creature chose this moment to attack him but, instead of biting Vallarin as he had Tolinev, the Goa'uld symbiote instead chose to take Vallarin as his new host. Vallarin thus became Marduk.