(Set after S3 finale) They're powerless, and Five and Klaus are having a harder time accepting that than the others. At least they have each other to rely on. (Klaus/Five) [Sorry, I suck at summaries]

Zerophilia - (noun) a rare condition that affects an unknown number of people. Everyone has an "X" chromosome, some have a "Y" chromosome, and even less are born with an extra "Z" chromosome. Following their first full sexual experience, zerophiliacs switch gender after experiencing an orgasm. This is a condition none of the Hargreeves knew about. Until they met Shaw. (Five is 19)