- "Not just any ship. This is the Achilles."
- —Daniel Jackson
The ship was used to keep the Stargate out of the hands of the Nazis as the Americans believed the Gate was a weapon. Her Captain was a merchant marine and the grandfather of Colonel Cameron Mitchell. (SG1: "Continuum")
In an alternate timeline, Ba'al traveled back in time to when the Stargate is on its way to the United States of America in 1939, to stop the formation of the Stargate program. His Jaffa boarded the ship and killed the crew, including the captain (because of this, Cameron Mitchell is never born), who is able to stay alive long enough to throw the Goa'uld bomb overboard and stop the destruction of the ship, allowing SG-1 of our timeline to gate there in 2008 and set things right. When the timeline alters and SG-1 attempt to gate to Earth, they arrive in the cargo hold of the Achilles, whuich has crashed in the north pole. In an attempt to create warmth, Mitchell blows a hole in the ice surrounding the hull, but this caused the ship to dislodge from the ice. SG-1 escape but Dr. Daniel Jackson gets frostbite in his foot, and the ship sinks to the bottom of the Arctic. Nearly a year later, the Russians retrieve the Stargate from the ship and begin to set up there own Stargate program. It is because of this SG-1 are able to restore the timeline, by sending Mitchell back 10 years before Ba'al gates back in time to the Achilles. Somehow, Mitchell is able to stow away on the Achilles and stop Ba'al and his Jaffa from taking over the ship, restoring the timeline. The real Ba'al finally dies on board when Mitchell shoots him in the head. (SG1: "Continuum")