Lantean citizen, Captain of the Ancient warship Tria, which saw battle in the great war with the Wraith some 10,000 years ago. Receiving word that Atlantis was being evacuated, Helia decided to take her ship directly to the Milky Way Galaxy. But while en route the ship's hyperdrive failed, and she was forced to continue forward at 0.999 the speed of light. Though the hundred crew members of her ship would experience only 12 years in passing, at least a million years would go by around them.
While deep in the expanse between the two galaxies, the Tria detected another ship. Reducing speed, they met the crew of the Daedalus, who ferried them back to Atlantis. There Helia, though grateful, initiated a lockout protocol which placed Atlantis in her hands.
Helia insisted that the day would come when modern humans would have a place in the city of the Ancients -- but until the time the Lanteans saw fit, she demanded the evacuation of the expedition from Earth. In an act of graciousness she permitted Richard Woolsey and General Jack O'Neill to remain as representatives. But soon the city was attacked by the Asuran Replicators, and Helia and all the surviving Lanteans were killed.
The Return, Part 1 - Helia and her crew are returned to Atlantis, and retake the city in the name of their people.