 Scully discovers that two worms put together will kill each other. When the investigators place one of the worms into the infected dog, it recovers. Against Scully's objections, Hodge and DaSilva try to place the other worm into Mulder and Hodge realizes that DaSilva is the infected person. He and Mulder restrain the hysterical DaSilva and place the last worm inside her. When they are rescued, DaSilva is quarantined and the others are released. Although Mulder wants to return to the site, he is told that it has been destroyed by the government.
