The Rikti invasion began with the appearance of thousands of glowing lights all around the world. Initially, the nature and purpose of these lights was completely unknown. The Freedom Phalanx made the determination, with the help of a former Portal Corp researcher, that the lights represented some kind of dimensional portal. Where they led no one could be sure. Long standing Freedom Phalanx member and renowned interstellar explorer, Star Strider, volunteered to pass through one of the portals and see what was there. Veiling himself in his invulnerable force field, he entered one of the larger portals and was never seen or heard from again. Similar experiments in other parts of the world had the same tragic results.
Soon after Star Strider's disappearance, Rikti soldiers came pouring out of the portals, at last revealing that the lights were, in fact, gateways to an alien dimension. It is assumed that Star Strider entered that dimension and was either captured or killed. If he survived his initial explorations, Star Strider's current fate is unknown. In order to end the Rikti invasion, a group of heroes known as the Omega Team passed through another portal and destroyed the aliens' primary power source. This closed the dimensional gateways, presumably trapping Star Strider behind enemy lines.