Amy: An experiment. Amy: And? Amy: Thank you, Sheldon. Amy: Very well. Amy: Zack. But recent events indicate that she may be a slave to her baser urges. Coitus. Howard: Leonard, settle this. Is this the Zack Johnson who used to have coitus with my neighbour Penny? It means intercourse. Nobody's touched each other. Penny: I'm suggesting there might be something you could do about Amy's urges? Possible explanations for your symptoms are, in descending order of likelihood, hyperthyroidism, premature menopause, hosting an alien parasite or, and I only include it for the sake of covering absolutely all bases, sexual arousal. Raj: Did he get superpowers? Ready, wrestle. She's horny. Sheldon: Amy's changed. Sheldon: The alternative would be to think backwards. Sheldon: Zack. This is going to decide who's the hero and who's the sidekick?
Plan: A: Amy; Q: Who discovers that Zack is not very intelligent? A: Penny's ex-boyfriend Zack and experiences sexual arousal; Q: What does Amy meet? A: Penny; Q: Who tells Sheldon that he should have coitus with Amy? A: Sheldon; Q: Who does Amy discuss her symptoms with? A: an alien parasite; Q: What does Sheldon think Amy has contracted? A: Howard and Raj; Q: Who argue about who would be the sidekick if they both acquired superpowers? A: a wrestling match; Q: How do Howard and Raj try to settle their argument? A: Leonard; Q: Who referees the wrestling match between Howard and Raj? Summary: Amy meets Penny's ex-boyfriend Zack and experiences sexual arousal. She later discusses her symptoms with Sheldon, though Sheldon prefers to assume that Amy has contracted an alien parasite. Later, when Sheldon discusses Amy's situation with Penny, she tells him that there is "something" he could do about Amy's "urges", meaning that he should have coitus with Amy, but Sheldon assumes that she meant Amy and Zack should have coitus. He arranges for them to meet again, but Amy discovers that Zack is not very intelligent, solving the problem. Meanwhile, Howard and Raj argue about, if they both acquired superpowers, which of them would be the sidekick. They try to settle the issue in a wrestling match refereed by Leonard, but they merely circle around threatening each other.