New info arrived this week for “The Lost Tribe,” the eleventh episode of Stargate Atlantis‘s upcoming fifth season — and the second half of the big, big mid-season two-parter. Along with part one, “First Contact,” the episode will guest star Stargate SG-1‘s Michael Shanks as Dr. Daniel Jackson.

As we reported previously, Daniel will visit the city of Atlantis in “First Contact” to do historical research on Janus, the Ancient scientist who invented a time-traveling Puddle Jumper and who helped save Dr. Weir when she traveled 10,000 years into Atlantis’s past (“Before I Sleep”).

Since we don’t know how the events of part one unfold, watch out for spoilers for that episode as we look at part two, “The Lost Tribe:”

Daniel and Rodney McKay have discovered a research laboratory on another planet. The lab once belonged to the Ancient scientist Janus, who tended toward inventions and experiments that the other Lanteans did not look upon favorably. And, much to their surprise, Daniel and Rodney are not the only ones there.

Meanwhile, “Todd” the Wraith (guest star Christopher Heyerdahl) has seized control of the power Earth battlecruiser Apollo, which has been outfitted with Asgard transporters, weapons, and defensive technology. Though he and his forces have subdued the ship’s 200-person crew, Ronon and Keller still remain at large. Todd accesses the ship-wide P.A. system and threatens to begin killing crew members unless they turn themselves in.

Christopher Heyerdahl returns as “Todd,” the on-again, off-again ally of the Atlantis team.

Todd is on his way to Janus’s laboratory, where he hopes to shut down a device (called the “Attero device”) that is threatening his new alliance. Racing to get there first is Atlantis’s Colonel John Sheppard and Dr. Zelenka, who know that Todd has hijacked their ship and is on his way to the facility. The two of them have joined up with a Travelers ship (“Travelers”), under the command of a Traveler captain named Katana.

In the hopes of getting his ship’s hyperdrive running at maximum output, Katana brings Zelenka and Sheppard into the aged and cluttered engineering room and introduces them to his chief engineer — Mila, who is only 15 years old. Mila has been working with the hyperdrive engine since she was 4 years old, and is a brilliant young woman who will do whatever is necessary to get the job done. Where Radek is cautious and doubtful that the job can get done (safely, at any rate), Mila shows him otherwise.

If they cannot reach Janus’s lab before Todd does, Daniel and McKay may not survive.

Guest characters include Daniel Jackson, Todd, Katana, Mila, and one of Todd’s Wraith (nicknamed “Kenny” in the script).

“First Contact” and “The Lost Tribe” are expected to go before cameras later this month. Part one should air on SCI FI Channel in the United States in September. While the cable network has not announced the schedule for Atlantis Season Five yet, based on past years we expect “The Lost Tribe” to premiere in January after a mid-season break of about three and a half months.

Stay tuned to GateWorld for the latest, and visit our Season Five episode guide to find out what is coming this season!