SG-1 prepares to visit a new world, one they hope will be a suitable place to relocate theEnkaran population. But as the Stargate is dialed, the seventh and final chevron fails tolock into place. All diagnostics indicate that the gate is working fine, and that there isno reason why it should fail.Carter discovers that the base power logs indicate an energy spike about eight minutesbefore they attempted to dial -- similar to when Maybourne's rogue Stargate team used thesecond Stargate recovered from Antarctica ("Solitudes,""Touchstone"). Seismic activity in Siberia, Russia preciselycorresponds with the energy spike, confirming that the Russians have a Stargate.
After confronting the Russian government, Hammond reports his findings to SG-1: the Russiansrecovered the alpha Stargate from the bottom of the Pacific Ocean. The U.S. swept the areawhere Thor's ship went down ("Nemesis"), and concluded thatthe gate must have been destroyed. The Russian navy, however, was on alert after thecountry discovered the Asgard ship in Earth's orbit. They recovered the gate.
The Russian government has been divided on whether or not to commission a Stargate programof their own. Now, the gate has been connected to another world and cannot be closed. TheRussian president was prepared to order the base bombed and the program covered up; but ascientist, Dr. Svetlana Markov, convinced the government to allow SG-1 into Siberia withher to try and find another solution.
The team meets up with Dr. Markov at Kuybyshev Airbase, and learn that she knows far moreabout them and about the SGC than she should. She explains that their Stargate program hasbeen in operation for 37 days, with Markov as second in command to General Sakalov. Theywere able to activate the Stargate so quickly because they have the DHD -- missing from theGiza dig where the Stargate was discovered in 1928, but recovered from the Germans afterWorld War II.
The five of them fly to Siberia, and parachute in. The base is quiet and dark, and the teamsoon discovers that all 47 of the people assigned to the project are dead. Some were shot;others died when the commanding officer enacted the extreme measures protocol and gassedthe facility.
But the Stargate remains connected to a water planet (where the gate on the other side isentirely submerged), despite the fact that it has no apparent power source (the extrememeasures protocol cut its connection to the DHD). The Russians had captured a water samplefrom the planet, though Dr. Markov was recalled to Moscow before she could examine it. Thebase officials were under orders not to touch the sample until she returned.
SG-1 must find a way to shut down the outgoing wormhole. Otherwise, they cannot use theirown Stargate -- and seven SGC teams will remain stranded offworld.
Markov explains that the water sample -- now missing from the containment area -- exhibited incredible energy properties (giving off energy in the form of heat). Carter theorizes thatthe Stargate may be drawing energy from the water on the other side to maintain thewormhole. Because a Russian probe on the other side has been transmitting a constant signalback through the gate, it hasn't shut down.
Markov, Carter and Jackson take a mini-submarine through the gate to the water planet, inorder to capture the drone and shut it off. They succeed, and the Stargate deactivates.But when they move the sub to investigate nearby ruins (and thereby try to solve the mystery of why everyone in the Russian base is dead), the sub becomes stuck. The enginesblow, and Dr. Markov sets about repairing them.
Back on Earth, O'Neill and Teal'c continue to search the base for survivors. Inside a freezer, they find the person responsible for leaking top secret information on the SGC to the Russians: it is Colonel Maybourne, frozensolid.
They thaw him out, and discover that, miraculously, he is still alive. When O'Neill andTeal'c refuse to let him get to the Stargate, a gasseous life form leaves him and entersTeal'c.
Maybourne explains his involvement in the Russian program to O'Neill, and what they discovered: the water isn't water at all -- it is a collection of millions of intelligent,microscopic life forms. They are trying to get home. The soliders in the base tried to stopthem, even shooting many of the scientists. It was chaos. The alien life forms insideMaybourne forced him into the freezer to avoid the nerve gas released by Colonel Sakalov,and kept him alive.
O'Neill follows Teal'c and tries to stop him from going through the gate and killinghimself, but Teal'c throws him aside and continues toward the gate room.
On the submarine, Dr. Markov repairs the engine -- but still, the sub will not move. As thepressure around them increases, the glass window shatters. Instead of filling the sub,though, the alien life forms create a solid wall of "water" where the window was. Danielputs his hand into the water, believing the aliens just want to understand them. But he, andMarkov and Carter, are soon pulled into the water.
Teal'c enters the gate room and dials the water planet. The alien leaves his body, andescapes through the gate, leaving him alive. Moments later, the Stargate reactivates andCarter, Jackson and Markov come flying through.
It was, Jack speculates, an exchange of hostages.