Max runs for fourth-grade class president — but his girlfriend Rose is running, too. DJ tries to make up with CJ, and Steph picks a fight with a clown.

Rodney McKay is reunited with his estranged sister back on Earth, who has given up a brilliant career as a scientist to raise a family.

The team desperately attempts to stop two Wraith hive ships from reaching Earth. Sheppard must rely on an old foe to rescue McKay and Ronon.

When an operative of the Trust plants a bomb in Atlantis, the team must find a spy within their own ranks before the Wraith arrive and discover the city.

Sheppard’s team meets a civilization about to be destroyed by a super-volcano, and is trapped there when the Stargate is destroyed during the evacuation.

Michael and his Wraith faction arrive at Atlantis to propose an alliance, hoping to use the retrovirus to transform their Wraith enemies into prey.

The Daedalus arrives to defend Atlantis from the Wraith onslaught, but it may not be enough when the team discovers that an even larger armada is on the way.

The Daedalus is infected by a Wraith computer virus, while members of the expedition hope to return to Earth.

As the Ori invade the Jaffa planet Chulak, Vala and Daniel must deal with their leader: Vala’s young daughter, rapidly aged by the Ori to serve their purposes.