Ravis was an alien who Hoshi Sato met on Risa in 2152. She became intent on learning his language, which was very difficult to master. He attempted to teach his language to her, without much success. He invited Sato to join him in the exotic steam pools of Risa, which she did. In the end, they went to bed together, and Ravis worried that Sato would feel that he took advantage of her. (ENT: "Two Days and Two Nights")