The Renai'i were a warrior species about which only legends and myths are heard. Their home-space was reported to lie somewhere beyond the Typhon Expanse. As of 2372, no known Federation or Starfleet starship had encountered the Renai'i. The Lelari held information about the Renai'i which, after gaining Benjamin Caldwell's trust, they shared with the Federation. The Lelari felt the Renai'i were not worth contacting. (Star Trek: The Cantabrian Expeditions: "Catalyst, Part One")