Conversion

S2, E8: Within hours following his encounter with the mutated Wraith child Ellia (Jewel Staite) Sheppard (Joe Flanigan) is shocked to find that his wounds have disappeared without a trace. Soon after he begins exhibiting other symptoms similar to the ones that plagued Ford following his own Wraith attack. Dr. Beckett (Paul McGillion) realizes that a small amount of the retrovirus that Ellia ingested is now in Sheppard's bloodstream -- and he is quickly mutating into the very creature that attacked him. As Sheppard becomes less lucid by the hour the team races against the clock to save his life and reverst he effects of the retrovirus.