Instinct

S2, E7: During a visit to a distant planet the team discovers a village whose inhabitants live in fear of a Wraith residing in their midst. When the team sets out to confront the creature they encounter Zaddik (John Innes) a scientist who has been living with Ellia (Jewel Staite) a Wraith child for the past several years. Zaddik has developed a serum that works to satiate the young Wraith's appetitie and prevent her from feeding on him. Dr. Beckett (Paul McGillion) is intrigued by the serum having been eager to test an experimental retrovirus of his own that could give the Wraith humanlike qualities and rid them of their predatory instinct. Beckett meets with Zaddik and his supposedly tame Wraith companion hoping he can begin a controlled experiment on Ellia. However when Ellia downs his retrovirus the underdeveloped formula has the opposite of the desired effect.