With the first half of Season Four’s mid-season two-parter about to air, details are skill sketchy as to what is to come in the second half, “Be All My Sins Remember’d.” Now some new hints about the episode are available, thanks to U.K. broadcaster Sky One.

The episode will further develop the war between the Wraith and the Replicators, initiated by the Atlantis team early this season (“Lifeline”). Having since learned that the Replicators are wiping out human-populated planets in order to eliminate the Wraith’s food supply, the team must now work with a Wraith scientist (who will be nicknamed “Todd” later in the season) to disable the artificial life forms (“The Seer”).

“Todd” (played by actor Christopher Heyerdahl), who also appeared in last week’s episode “Miller’s Crossing,” will play a significant role in the eleventh episode. Here is how Sky One describes the episode:

The Atlantis team strives to eliminate the Replicators once and for all, but with time in short supply they may well have a crisis on their hands.

The second half to the two-part mid-season special sees the team make contact with the enemy fleet after allying themselves with a Wraith scientist. For the first time in Stargate history, the two are ready to fight together against a common enemy. But is the new-found friendship what it seems? A war is brewing, but between who remains to be seen.

The episode also guest stars Jill Wagner as Larrin (“Travelers”) and Michael Beach as Apollo commander Abraham Ellis, and features the return of Mitch Pileggi as Daedalus commander Steven Caldwell.

Part One of this story, “This Mortal Coil,” premieres Friday, December 7 at 10 p.m. (Eastern/Pacific) on SCI FI Channel in the United States, and Tuesday, December 11 on Sky One in the United Kingdom.

“Be All My Sins Remember’d” airs January 4 in the U.S., and January 8 in the U.K. Learn more in GateWorld’s Season Four episode guide!