Orlin had been an ascended Ancient who existed among the Others on a higher plane. The most sacred rule of the Others is not to accelerate the natural ascension process of those beneath. However, when Orlin broke this rule by helping the inhabitants of Velona to build a powerful weapon for self defense, the Others destroyed the planet and banished Orlin alone on Velona for hundreds of years. When SG-1 visited the deserted world, Orlin followed Carter back through the stargate, retaking his human mortal form in order to stay with her on Earth. Pursued by the NID, however, he built his own stargate in Carter's basement, using components bought online including 100 pounds of pure raw titanium, 200 feet of fiber-optic cable, seven 100,000-watt industrial-strength capacitors - and a toaster. He escaped back to Velona to prevent the SGC from testing Velona's Ancient weapon, and for this the Others granted him a second chance, allowing him to ascend once again.
As the Ori prepared to invade the Milky Way Galaxy, Orlin again risked punishment by the Others and chose to intervene. Once again he retook human form, but in order to preserve his Ancient knowledge, he returned as a child. The knowledge he possessed as an ascended being was too massive for a normal human brain to handle, however a younger brain would give him a slightly better chance of retaining the knowledge a little longer since the neural makeup of a still-developing mind has the potential for better memory retention than that of an adult. He wasn't certain why the Others permitted him to descend with his knowledge intact, although he considered that perhaps enough of them felt it was necessary for someone to step out of line to warn Earth about the Ori, but he knew he was taking an enormous risk. Most likely the Others would not help him to ascend again, and ultimately he would lose the knowledge of the Ancients.
At the SGC, Orlin worked with Carter, helping to complete an anti-prior device that would neutralize a Prior's special abilities, and working to find a cure for the Prior plague that was ravaging Earth. As an ascended being, he had the power to simply cure the disease, but as a human he struggled to retain the Ancient knowledge that would enable him to synthesize a cure using Earth's medical technology and a sample of the Prior's blood. However, the human brain is not meant to hold that much information, and his brain cells began to die from the intense synaptic activity. Readings from the brain scan device showed that pockets of cells were shutting down, as if wearing out from extremely unnatural overuse, and as a consequence of trying to hold on to the Ancient memories, Orlin was damaging his own brain. The significant and progressive degenerative process started to impair cognitive functions, and Orlin became more and more forgetful until he had to remove himself from the research, but after Gerak had cured the plague victims on the base, the SGC was able to isolate an antibody and rely on Orlin's research to manufacture a vaccine that would prevent the spread of another plague. For Orlin, however, the damage had been done. Although his condition stabilized, the brain damage was irreversible, and he was institutionalized in a residential care facility with no memory of his past or his own identity.
Portrayed by: Sean Patrick Flanery, Cameron Bright