Su Chen-Mai was a male Human in the early 24th century, born in Guangzhou on Earth. As of 2336, he was a mercenary for hire, and that year was recruited by Asfar Qatala agent Talma Pren to investigate legends of an interdimensional portal on an unnamed planet near the Cardassian border. To this end, Chen-Mai hired xenoarchaeologist Ven Kaldarren and pilot Lam Leahru-Mar to search for the ancient site. Chen-Mai was killed when the USS Enterprise-C, in defending themselves from a Cardassian patrol vessel, triggered a massive solar flare which engulfed the planet. (TLE novel: Well of Souls)

Kaldarren had introduced Chen-Mai to his son, Jason Garrett, as an old friend of his from the Tarkava Institute on B'Utu Aura. However, this was clearly a cover story to keep the boy from knowing about the questionable legality of their mission.