Tom, greeting-card writer and hopeless romantic, is caught completely off-guard when his girlfriend, Summer, suddenly dumps him. He reflects on their 500 days together to try to figure out where their love affair went sour, and in doing so, Tom rediscovers his true passions in life.
Routinely exploited by her wicked stepmother, the downtrodden Samantha Montgomery is excited about the prospect of meeting her Internet beau at the school's Halloween dance.