Percy calls the president the United States (guest star CAMERON DADDO -- 24) & threatens to set off a nuclear explosion unless his demands are met. Birkhoff finds two scientists who could help stop Percy's new nuclear satellite, so Nikita & Michael head after one & Sean & Alex look for the other. Unfortunately, Alex & Sean get caught at the very location that Percy blows up as an example of his power & Nikita realizes the best way to stop Percy is to go into the belly of the beast: Division itself.