Chuck runs into his ex-girlfriend (Jordana Brewster) while on a Nerd Herd call.  In an attempt to look cool to her, he lies and claims he's more successful than he is.  But when Chuck has a flash on Jill's boss, a scientist who has apparently developed a deadly bio-weapon, he, Sarah and Casey have to investigate to find out if Jill is involved.  Meanwhile, at the Buy More, Big Mike nearly chokes to death which leads to a mandatory CPR course taught by Devon.