It wasn't until the beginning of Stargate SG-1's fourth season that fans knew to take the Replicator threat seriously. The spidery nasties had only seemed like one of many new enemies introduced in previous years. But when the one seemingly omnipotent backbone of the galaxy was asking Earth for help, clearly we were in real trouble! In fact, the team's list of enemies expanded and got far more complicated this year. Proving without a shadow of a doubt that this is science fiction, the Russians reveal they have their own Stargate program and ask the Americans for help. This twist allows for exploration of all the political machinations occurring behind the scenes of the SG-C, all of which appear to stem from the embittered Senator Kinsey (Ronny Cox).

There were quite a few Earth-based stories in the year, but not all the new enemies were originally local. Willie Garson comically guest-starred as Martin, a geekily suspicious guy with too much knowledge of the Stargate. More sinister was an old flame of Daniel's turning into something far more painful than an old wound (thanks to an ancient Egyptian curse). Thankfully, the writers hadn't forgotten the importance of one-off storylines too. In "Upgrades" the team learns a lesson in abuse of power. In "The Other Side" (featuring DS9's Rene Auberjonois) they learn about blind trust. In "Scorched Earth" a dangerous claim for a planet's ownership means they learn to value Daniel's contribution to the group dynamic. If only this last lesson were learned better, season 5 might not have ended up as muddled as it did.