When Alex screws up on several WOOHP missions, she begins to seriously doubt her spying abilities. Then, when Jerry introduces the girls to Britney -- a pretty, smart, sweet, spy-in-training who's been assigned to help them on their next mission -- Alex only feels worse. In fact, she thinks she's on the verge of being replaced. When she screws up again and lets a villain (who's invented a device that literally slows people down) escape, she decides to quit WOOHP altogether. In a b-story, Alex does an extra credit project for science class (about molecules) that helps her stop the bad guy, save her girlfriends and gain her confidence back.