The Siege (Part 1)

McKay leads a team to activate the Ancients' orbital weapons platform to destroy the hive ships on the final stretch to the city. After the team has found a potential Atlantis Alpha Site (M1K-439 as "Planet Waterfall", the Tyrannosaurus-like planet M1M-316, the Genii-infested M4H-212, and M85-393 with intense daytime temperatures were rejected), the city's personnel are preparing for evacuation, when they discover the kamikaze dart pilot ("The Brotherhood") has survived in the city.