Greyson Sanborne has had a varied career, beginning with being a pilot in the Navy, a tour of duty in the SEALs. He was later recruited for covert operations by General Kyle Dalton. During his last mission, the destruction of a downed weapons platform in Colombia, his entire team, including his love, was killed; betrayed by Alec Marx, a last minute addition to his unit before the mission.
Sanborne was spared the fate of his unit only by a chance discovery of an alien space craft, piloted by Geheran. Captured together by a Colombian patrol, they later escaped together. After Grey's discovery of the fate of his team, he accepted an offer from Geheran to come with him to his world. In hopes that the alien might be taking him to his death, Grey accepted.
Instead of death, Grey found compassion from Geheran and his mate, Sheral, who helped him get past his grief and find a renewed purpose to his life.
Sanborne later returned to Earth, keeping his knowledge of the Trephi a secret. He managed to get a position in the US Secret Service working with his former Naval copilot, John Drake.
One day while on assignment at a presidential speech, Grey recognized a member of the crowd wearing a SDF uniform. A brief fight with a nervous Nicia, led to her unintentional capture. Grey later helped her escape. A reunion with Marx let to his discovery of the truth about the death of his team and a later discovery that Marx held Nicia's mother, Sheral, captive for the past six months.
Grey staged a successful rescue and later turned himself in to his superiors in order to deliver an alliance proposal from the Trephi to Earth's governments.
The subsequent trial led to his being discharged from the secret service and banned from any further government positions. The Trephi, unhappy with the verdict of Grey's trial, offered him a position within the SDF.
Grey accepted their offer and currently acts as the Trephi Emissary to Earth alongside his mate, Nicia.