As nice as it would have been to maintain the new season high set by “The Lost Tribe,” the October 17 episode “Outsiders” slipped back down to the season average territory. The twelfth episode of Stargate Atlantis’s fifth season earned a 1.2 average household rating, according to the SCI FI Channel.

This is down three-tenths of a point, or 20 percent, from the previous week.

“Outsiders” brought Colonel John Sheppard and his team to a planet where a group of refugees — survivors of Michael’s Hoffan plague — had resettled. When the Wraith arrive, the village’s native inhabitants are challenged to hand over the refugees or be destroyed themselves.

The episode guest starred Paul McGillion as Dr. Carson Beckett.

Ghost Hunters led the cable network’s ratings for the week, with a 1.9 rating. Amanda Tapping’s new show Sanctuary earned a 1.6 rating (for “Folding Man”), staying even with the previous week. Destination Truth turned in a 1.3.

Another new episode of Stargate Atlantis, “The Prodigal,” airs this Friday at 9 p.m. Eastern and Pacific (8 Central) on SCI FI!

(Thanks to Morjana for the tip)