The Lost Tribe (Part 2)

Sheppard and Zelenka survive the Stargate explosion, but the city is severly damaged. Todd forces Sheppard to give up the location of the Attero Device and heads there in the Daedalus, but is disabled by Ronon and Keller who escape Wraith capture. Keller is captured and the Wraith fix the hyperdrive and continue their journey, but their delay allows Sheppard, in a Travelers ship sent by Larrin to reach the planet first and engage the aliens who are revealed to be rogue Asgard. Todd and the Wraith flee the Daedalus after sending it on a collison course, but Sheppard saves the ship. McKay and Jackson escape and disable the device, but Jackson is badly injured before the Daedalus rescues them. Sheppard's ship defeats the Asgard, except one ship that flees and then destroys the facility where the Attero Device is to prevent it from ever being used again.