THE EX-FACTOR: Lindsay joins Summer and Marissa for a girls' night out where they bump into Alex and her ex...who's also a 'her'. Summer finds out that the whole water polo team knows that it's her and Zack's 6 month anniversary. THE ACCOMPLICE: An old friend from Sandy's college days comes back with a request that could threaten the Cohen's marriage. Marissa skips school to hang out with Alex while Summer rediscovers Seth's feelings. THE SECOND CHANCE: Ryan interferes with Lindsay and Caleb's relationship while Sandy's is compromised by his agreement to help his old girlfriend. THE LONELY HEARTS: Valentine's Day finds the OC while Zach, Summer and Seth drive to LA to pitch their 'Atomic County' comic. Ryan 'Cruises' onto Caleb's good side while Marissa and Alex cross over into the dark side. Congratulations: Your vote has been cast