The Scourge

The Scourge is the seventeenth episode of the ninth season of Stargate SG-1.

Plot
General Landry cancels a mission of SG-1 and instead orders them to do some "babysitting" for a group of foreign diplomats of the IOA, which is currently funding most of the Stargate program. The team, together with the representatives Richard Woolsey (US), Shen Xiaoyi (China), Jean LaPierre (France) and Russel Chapman (Great Britain), visits the "Gamma Site", one of Earth's off-world bases where scientists are currently, among other things, interested in an alien bug called R-75. It is supposed to originate from the Priors as a new form of threat to worlds where the Prior plague has been defeated, feeding on plants to destroy them completely.

However the scientists discover soon that after being deprived of food, the bugs now start to feed on meat as well and that causes them to multiply rapidly. Meanwhile the Chinese ambassador complains that her country hasn't been given any of the technology which Stargate Command acquired, although they also signed the Gate Alliance Treaty. Meanwhile Dr. Myers is bitten by one of the bugs which makes him ill, soon after he is taken back to Earth. However, before they can enter the Stargate the bugs leave Myer's body and swarm the gate room. Therefore the room is sealed and SG-1 and the diplomatic team are locked down and can't return to Earth.

Following emergency routine, SG-1 and the diplomats are sent to the surface and try to make their way to a research station, at which point they are attacked by the bugs, who escaped the base and burrowed through the earth. Although one soldier is lost, the team retreats to a cave; the bugs are unable to burrow up from underneath, and the team is able to use gunfire to hold the entrance.

Meanwhile on Earth, the SGC is partially aware of the situation. Since they believe all people at the Gamma Site are dead, General Landry sends the Odyssey to the planet with instructions to destroy the bugs from orbit "As per Protocol CR-91."

Back on the planet Jackson and Shen Xiaoyi again argue about China's position in the Stargate program while another soldier is killed by the bugs. Mitchell and Teal'c decide to try to get back to Gamma Site and get a F-302 fighter to retreat far off but find out that the base was destroyed by its self destruct system. Retreating back to the cave their only hope now lies with the Odyssey. The only problem is that the beacons SG-1 have won't work with the atmosphere (which has a strong ionosphere interference) and thus the Odyssey most likely would proceed with emergency protocol and poison the whole planet to kill the bugs.

Thus SG-1 try to reach the research facility where Carter would be able to send a signal to the Odyssey to pick them up. They reach the research station, but must hold off the bugs until the Odyssey can pick up the signal. This task is done by Mitchell, Daniel and Teal'c, while Lt. Col. Carter prepares the signal. After a desperate holding action, the plan succeeds and the team and the diplomats are beamed up to the Odyssey just as they run out of ammunition and the bugs flood the base. Despite the disaster, the IOA deems that the incident was beyond anybody's control, and decides to continue funding the Stargate program. However, Landry informs SG-1 that two other planets were attacked by the bugs.