Kelly accepts Brandon's marriage proposal; David buys a gun to protect himself; Noah's old friend Gwyneth reappears in his life.
Archer, Reed, and Hoshi are exposed to a highly contagious virus that transforms their bodies, minds, and memories into those of long extinct aliens from a tropical world.
A lonely telepath begs Hoshi to visit his faraway planet in exchange for information on the Xindi, then refuses to allow the linguist to leave.
With everyone back in school, Carol (Suzanne Somers) decides to take the same college classes as Karen (Angela Watson).