Ryan leaves Newport to visit his mom, but before they meet he has a steamy encounter with his mom's coworker. Back in Newport, Seth is still keeping secrets and Taylor and Summer devise a fool-proof plan to figure out what's going on with him. Their plan backfires and Summer is left devastated. Julie Cooper pays Volchok a surprise visit and gives him some stern advice. Then Marissa confronts Volchok's friends and helps a girl get out of an intense situation at a raging party. Meanwhile, Sandy puts an end to the trouble with Matt but leaves Kirsten at home alone.