Series: Stargate SG-1Episode begins with SG-1 preparing to go to a planet to observe a black hole, which is made possible by an impending eclipse. As they are heading out, Teal'c is asking Carter about black holes, when O'neill suddenly explains the phenomena surprisingly well. Daniel and Teal'c are shocked, as Carter comments, "What? He doesn't have that telescope on his roof for nothing."As they arrive through the gate, they find that the welcoming committee is unexpectedly absent. They proceed towards the outpost, when they come across a dead body lying by the road. Quickly putting on gas masks and gloves, they explore the rest of the town, to find that everyone is dead.They dial Earth to report the situation, and a hazmat team is sent through to check them out. Fraiser finds that they escaped contamination, and it must have been some sort of disease that wiped out the people. The team returns in full hazmat gear to document the dead and decontaminate the area. As they are tagging bodies, they come across a small child hiding in the bushes. Surprisingly, a young girl survived. They comfort her and bring her back to the outpost.Fraiser finds that the girl has the presence of naquadah in her blood, which may be why she survived. As they prepare to leave, Carter mentions that they should continue with the observation of the black hole, as this is perhaps their best opportunity to do so. Jack notices that the girl has formed a bond with Carter and sends her back, while himself and Teal'c will handle the observation. Carter agrees to stay with the girl and keep her company, as she seems to not want to be alone.Fraiser and Daniel meet with Hammond, and explain that the disease may have been caused by bacteria brought from Earth that mutated and wiped out the people. But they might have the cure in the girl, who may hold the key to treating other diseases. Carter and the girl have kept busy drawing pictures in the room. At one point, she draws a picture of her standing in a field crying, with dead bodies everywhere. Sam then draws herself standing next to her, and says "You're not alone anymore." When Carter tries to leave at some point, the girl stops her, and she finds out the girl is named Cassandra, and she begins to speak some more. Cassandra then complains that she's feeling pain in her chest, so they go get checked out by Fraiser. They believe it's low potassium, when she suddenly collapses. Fraiser hears a strange noise in the girl's heartbeat.They perform an xray, and find that some sort of object has appeared next to the girl's heart. They perform a biopsy, and as the doctor reaches and begins to take a sample of the object, it stops her heart. Luckily, her heart restarts once he pulls the scope back out. Using the samples obtained, they find that one half of it is made of naquadah and the other iron and potassium, separated by a thing layer of fatty tissue. Carter then performs an experiment to find out what would happen if the two sides touch. What results is a huge explosion, and Carter only used microscopic samples. Hammond decides that they need to return the girl through the stargate, before the device in her chest explodes.Meanwhile, Jack and Teal'c wait for the eclipse to happen, and they notice a strange blip appear in space. As they zoom in, they find that it is a Goa'uld ship. Teal'c says that they must leave NOW. As they run for the gate, Teal'c talks about one Goa'uld, Nirrti, who used a trick to destroy his enemies. He would send an ambassador through the gate to meet with his enemy. As the ambassador left to return through the stargate, the gate would be destroyed somehow. Jack realizes that the girl is probably the same tactic. He and Teal'c rush to the gate with death gliders firing on them.Back on Earth, they are preparing to dial the gate and go back. As they wait for the sequence to complete, Cassandra collapses again. However, before they can dial out, Jack and Teal'c dial in from the planet and leap through amid a cloud of debris from a glider shot. Jack tells them to get the girl away from the gate! Recounting Teal'c story, they determine that the girl was this same trick, since the Goa'uld knew they would discover her amongst the death and bring her to Earth. They decide to take her to an abandoned nuclear facility nearby as they figure they have 30 minutes until her time is out.When they arrive, Carter goes down the elevator with Cassandra, and is told she only has a few minutes to turn around and come back up. On the way down, Cassandra wakes up, and Carter is very emotional trying to keep her calm. They reach bottom and Carter takes her over into a small room. She tells her that she has to go for a few minutes, but she'll come back. As she starts up the elevator, she can't handle it anymore, and returns to the room. O'neill uses the intercom to ask her why she went back, and Carter said she was awake and she's staying with her. Tense minutes pass as the time runs up...with no explosion. Turns out they're both fine, it didn't happen.Apparently once she got far enough away from the gate, the bomb started to be reabsorbed by the body. They decide that Fraiser will adopt her for the time being, and they come up with a cover story about how she came from Toronto. The episode ends in a park with Carter teaching her about swings as the rest of the team smiles.
Episode: Season 1, Episode 14
Recapper: Shadow Penguin
Tropes used in "Singularity" include: