M3T-842 was a planet in the Pegasus galaxy used as a Wraith outpost. Doctor Rodney McKay was able to identify the planet as somewhere that had never dialed Admah or been dialed from Admah, making it a place that Lieutenant Colonel John Sheppard's team could escape to. Major Evan Lorne led a team to the planet to await Colonel Sheppard's team but found a complication in the form of a landed Wraith hive ship. When Sheppard's team arrived, McKay was able to use a weapon from Admah to hold off the Wraith while the Daedalus, dispatched by Richard Woolsey, laid down covering fire long enough for the team to escape through the Stargate to Atlantis. (SGA: "Brimstone")