Sybo was an Argelian woman and the wife of Prefect Jaris. She lived with her husband in their home in the chief city.
As a descendant of the priestesses before the Great Awakening, Sybo was among the few with the ability to conduct the Argelian empathic contact, a method of discovering hidden feelings and the truth about crimes. Sybo employed the method to find out the truth about three murders in 2267, of which Montgomery Scott stood accused.
During the contact she felt the presence of the Redjac entity and spoke of it to the others, but before she could tell where the entity resided, she was murdered by it, and again all evidence pointed to Scotty. (TOS: "Wolf in the Fold")
Sybo was played by Pilar Seurat.