First aired: 5/19/2008 Production Code: 3T6616 Penny's break-up spurs Leonard to summon the courage to ask her out, and each goes to Sheldon for advice on their upcoming date.

When Jenny returns from her European trip, the entire NCIS team will be forced to take a Homeland Security polygraph test, and the deepest secrets of each agent are about to be revealed. Plus, an unarmed Tony and Jeanne are held hostage by a ruthless drug dealer.

A casino employee is beaten and raped on her way home from work, but she survives and identifies her attacker. Unfortunately, a DNA test sets him free and Grissom must wrestle with whether evidence can ever lie. Later, Grissom comes to the rescue of a coworker who ends up on the other side of the law

With Piccolo gone, Android 17 has no choice but to fight Cell on his own or so it seems, that is until Android 16 steps in to fight. As the battle rages on, it is easily noticeable that Android 16 is just as strong as Cell, but can the silent giant Android 16 defeat Cell? Or maybe this fight will buy Vegeta and Trunks the precious time they need to complete their training in the Hyperbolic Time Chamber.

Skyler's frustration with Walt's secrecy boils over; Jesse is dealt a devastating blow that leads him down a path of self-destruction, and only Walt is willing to help him; and a grief-stricken Donald experiences more tragedy.