Thirteen has been in prison for the past six months, but the real mystery for House is what she did to get there. When she exits the prison, Thirteen is surprised to find him waiting for her, and unaware of his plans for the two of them for the next few days. As House probes Thirteen for more information, intent on solving the puzzle of her disappearance and mysterious incarceration, they travel to an annual spud-gun competition. The two join forces to compete against House's much younger, overconfident rival, and along the journey uncover secrets and truths about each other. Meanwhile, at the hospital, the team treats a science teacher suffering from severe respiratory illness, and when the team inspects the patient's house for clues, they learn he's a hoarder. But upon a second visit to the house, they uncover something shocking among the many piles. Also, Taub tries to get back into the dating scene.