marissa cooper dies in an accident in an episode named the graduates. Earlier in the day, they graduated, as stated by the name, and Ryan gets a car from his mum. Volchek, is angered that he can't have Marissa, he therefore tracks them down.
Episode 24, of series 2: The Dearly Beloved. This is the final episode of season 2, and many events have gone on in the last few weeks. Trey and Marissa find themselves alone on the beach drinking, and Trey goes a little too far. Ryan finds out about this, and decides to settle it with Trey
