The SG-1 team gets leave time as Daniel Jackson (Michael Shanks) had his appendix removed. Just after Major Carter (Amanda Tapping) declines Colonel O'Neill's (Richard Dean Anderson) invitation to go fishing, O'Neill is beamed aboard the cloaked Asgard ship "Beliskner" orbiting Earth. Encountering bug-like robots, O'Neill learns from the dying Asgard, Thor, that the creatures are called Replicators. They ingest the ship's alloys in order to self-replicate and will eventually land on Earth in the search of more raw material. O'Neill contacts Stargate Command with a request to beam up explosives, however, General Hammond (Don S. Davis) also sends along Carter and Teal'c (Christopher Judge) against O'Neill's wishes. An Earth shuttle may be sent to pick them up later.