S1, E4: Chuck takes on an unusual task when Sarah's hot colleague from the CIA requests help with a mission. He finds out that a million-dollar diamond hidden in a Malibu mansion is being used to help fund terrorists and must help these two beautiful women steal it back. Meanwhile, Chuck begins to realize that Sarah's double life, which she is very good at maintaining, really makes it hard for him to get to know who she really is. And Morgan tries to get Chuck to set him up with Sarah's friend.