Ancient warship under the command of Captain Helia. Though the war would ultimately be lost, the Tria fought successfully in the against the Wraith until they were battle scarred by multiple Wraith cruisers. When the order was delivered to recall to Earth, Helia elected to proceed back to the Milky Way directly.
Half-way through their journey, while caught in the deep void between the Pegasus and Milky Way galaxies, the Tria's hyperdrive failed. Instead of limping back into Pegasus, Helia chose to press on at 0.999 the speed of light. Though a million years would pass around them, they would return to Earth in less than 25 of their years.
Halfway on their journey the Tria detected the presence of another vessel which had maneuvered alongside their position as they passed by. Reducing speed, Captain Helia found the Daedalus, and immediately requested hyperdrive transport back to the city. The ship's final fate remains unknown, as the Ancients who occupied Atlantis were wiped out by the Replicators. Presumably it engaged the enemy during the attack, and was destroyed by superior forces.
The Tria was manned by just over a hundred officers.
The Return, Part 1 - The Tria detects the Earth ship Daedalus performing a sensor sweep as the ship passes, and reduces speed to meet the Lantean descendants.