A Xindi-Primate, Thalen was one of Degra's assistants. In 2153 he was captured by hte NX-01 along with Degra, and was fooled by an elaborate scheme concoted to reveal the location of the Xindi weapon. Afterward his memory was blanked of the incident and he was returned to Degra's ship. [2] Degra celebrated the completion of the Xindi weapon with Thalen. [3] 