"The Siege" is the season finale for season one and season premiere for season two of the military science fiction television series Stargate Atlantis, and the nineteenth, twentieth and twenty-first episode of the series overall. The episodes were written by executive producers Joseph Mallozzi and Paul Mullie (part two) and Martin Gero (part one and three), and all three were directed by Martin Wood. The episodes were one of the series strongest in season 1 on Nielsen ratings and part three gathered the strongest rating with "Instinct" in season 2. The episode got strong reviews from major media publishers worldwide. Part three introduced several cast changes for the season, including the departure of Aiden Ford (Rainbow Sun Francks) and the inclusion of Dr. Carson Beckett (Paul McGillion) and Steven Caldwell (Mitch Pileggi) to the main and recurring cast. "The Siege" is about the Wraith laying a siege on Atlantis and the Atlantis expedition's re-contact with Earth. Plot Part 1 While the Wraith come closer to Atlantis, the leading group of the expedition is informed by Rodney McKay and Radek Zelenka that the Wraith will pass the last Lantean defence satellite; they are very confident they can bring it back online and obliterate all three Hive Ships before they even reach Atlantis. McKay volunteers for the mission to power it up, entering the airless, weightless environment with a Naqahdah generator tethered to him, with it bobbing about like a helium balloon on the end of a string in an atmosphere within a gravity well. Meanwhile, Elizabeth Weir, John Sheppard, his team, and Bates search for a new Alpha site. Weir is informed by Zelenka that the self-destruct of the city wouldn't destroy enough of the city to prevent the Wraith from tracing them back to Earth. He shows Weir a simulation which predicts that the Wraith will be able to recover some of the City's technology, and some of the database. After an attack by darts on Atlantis and subsequent unexplained faults, it is suspected that one Wraith has infiltrated outlying parts. With a biometric sensor they are able to locate the Wraith and they try to capture him. However, the Wraith is able to fend off Sheppard's team until he is stunned by Aiden Ford. The Wraith is imprisoned and Sheppard starts to interrogate him after he named him Bob, but he keeps silent. Meanwhile, the Wraith Hive-Ships drop out