Col. Sean Grieves was on death row for high treason for abusing the use of the Antarctic Stargate in rogue NID operations that stole technology from Earth's allies. He sacrificed himself when attempting to fix a piece of defense technology that he broke on his rogue mission to the planet Latona. (5.20 "The Sentinel")
Col. Sean Grieves was one of the rogue NID agents who was arrested for high treason when Col. Jack O'Neill revealed the location of their operations through an covert sting operation (3.18 "Shades of Grey"). While he was an operative, Col. Grieves led a team to study an alien planetary defense system called the Sentinel. During his operation, along with his technical assistant, Lt. Kershaw, he killed the man who was assigned to watch over the Sentinel, called the Caretaker. In order that their presence in the Sentinel cave not be detected, Kershaw rigged the Caretaker's deadman switch to indicate that he was still alive. As long as the flame this switch controlled burned in the planet leader's office, the people of Latona knew that the Sentinel was operational and ready to protect them.
Two years after their mission to learn the secrets of the Sentinel and their arrest, the Latonans came under attack by the Goa'uld System Lord Svarog. SG-1 recruited Grieves and Kershaw to go with them on the mission to extract SG-9 who was present on the planet when the Goa'uld's Jaffa ground troops attacked and to repair the Sentinel which was obviously no longer functioning properly.
Jack knew that Grieves was not to be trusted. While stealing a powerful beam weapon from the people of P3Y-294, Grieves turned the device against his pursuers, killing all three. After the Jack's operation revealed the rogue cell, the SGC returned the stolen weapon but the government of P3Y-294 would have nothing further to do with Earth. General Hammond was concerned for SG-1, SG-3, and SG-9 because they could not trust Grieves.
Unfortunately, Lt. Grogan was the only survivor of SG-9. The rest of his team was killed by Jaffa while trying to get to the stargate. Jack asked that Grogan help him gain access to the city where the leader of Latona, Marul, had his office. It was time to talk with him about relocating his people. While they were gone, Carter and Teal'c set up a protective perimeter at the Sentinel cave while Grieves, Kershaw, and Daniel attempted to disengage the force field which prevented access to the device. Grieves lost patience with Daniel and heard the battle raging around him and asked that Daniel give him his Baretta while Daniel continued to assist Kershaw. Grieves took the gun and joined Carter in the defense of their position, but Carter called for them to retreat to the cave itself when the number of Jaffa became too overwhelming.
Daniel was successful in bringing down the force field on the Sentinel cave, something that took Grieves and Kershow 48 hours to do on their previous mission. Once inside, they decided to bring the force field back up. Kershaw was successful in doing so, but she was wounded by a staff weapon blast. Daniel was able to decipher the symbols on the Sentinel enough to give Grieves and Kershaw the last piece of information they needed to get the Sentinel operational once more. The device worked only when its Caretaker "joined" with the machine to activate it. They didn't put the device back together erroneously after all.
Jack and Grogan were captured by the Jaffa and taken to the Sentinel cave where they were tortured in front of their teammates. The Jaffa wanted access to the Sentinel so that they might destroy it. Grieves said that he could deactivate the force field from where he was standing next to the Sentinel, but he was bluffing and instead of bringing down the force field, he "joined" with the Sentinel and activated its powerful beaming system. All the Jaffa and the attacking mothership were whisked away to the place where the builders of the Sentinel had deemed appropriate. We are never told where this place was, but it could be that these individuals were all killed.
Grieves disappeared with the rest of the attackers and Kershaw died of her staff wound. All information that they might have gathered about the operational capabilities of the Sentinel died with them and it is fairly certain that Latona cut off all relations with the SGC following these events.
- Col. Jack O'Neill
- Dr. Daniel Jackson
- Maj. Samantha Carter
- Gen. George Hammond
- Lt. Grogan
- Lt. Kershaw
--DeeKayP 11:14, 17 Oct 2004 (PDT)