Stargate Atlantis is a popular series on the Sci-Fi Channel. It’s a spin-off from Stargate SG1. The first part of this article was an introduction to the show and a discussion of season one. Seasons two and three (and a little bit of four) are talked about in this article.

The Atlantis gate team loses one of its members during the Wraith attack at the end of the first season which paves the way for Ronon Dex. He’s from a planet that the Wraith completely annihilated. Ronon was left alive and used as a runner, which means that the Wraith planted a tracking device on him and hunt him for sport on various planets. He’s managed to kill many Wraith, but he’s also led them unwittingly to other human civilizations. Beckett was able to remove the transmitter and Ronon eventually joins the team. He’s an extraordinary soldier and his fighting skill has helped out the team on numerous occasions.

Introduced in season two is a Wraith retrovirus, devised by Beckett. It basically subdues the insect part of Wraith DNA and lets the human part take over. This virus figures into the last few episodes of the second season. The Atlantis team uses the retrovirus on one Wraith. They call him Michael and he soon discovers what the humans did to him – and he’s not very happy about it. He manages to escape Atlantis and is recovered by Wraith. Thus, Atlantis’ cover is blown; the Wraith know the city survived.

But, the Wraith are also facing civil war since they woke too soon. There are too many Wraith and too few humans. So, Michael comes to Atlantis with a Wraith Queen and they propose an alliance. This Queen wants to use the retrovirus on her enemy Wraiths, turning them into humans and thus food. This will create a balance in the galaxy again, she claims. Things go awry. It turns out, apparently, that the Wraith were not interested in the retrovirus; they were just trying to get information out of Atlantis about Earth, a perfect feeding ground. They succeeded and season two ends with the Wraith on their way to Earth’s galaxy.

In season three, the Atlantis team manage to stop the Wraith’s journey to Earth. In fact, they are able to turn many Wraith into humans and strand them on a distant planet. We learn a little bit more about the Wraith, too, as Sheppard is captured by the Genii and put in a prison with a Wraith who’s also been captured - and is very hungry . Sheppard learns first hand that they can suck the life out of people, but they can return it as well. He and the Wraith eventually help each other escape.

Another enemy is revealed in this season: human form Replicators. It seems the Replicators were first made by the Ancients to fight the Wraith but the Ancients deemed them dangerous and tried to destroy them. Now, McKay has actually made them more dangerous by giving them the ability to alter their own base code. They want to exact revenge upon the city. About this time, a lost warship full of the Ancients also returns and they decide to reclaim Atlantis. But the Replicators attack at the same time and they take over Atlantis. Sheppard and his team come up with a plan to retake the city and once again it comes under Stargate Command’s control.