Composer and musician Peter Bretter, unmotivated in life, is unceremoniously dumped by his girlfriend of five and half years, Sarah Marshall, the star of the hit television show, Crime Scene. Peter is devastated as he is in love with Sarah, who has left him for another undisclosed man. The situation is made all the more difficult for Peter as he also works on Crime Scene. Peter's stepbrother, Brian Bretter, trying to be his voice of reason, tells Peter among other things to go away on vacation to forget about Sarah. The place Peter chooses is the Turtle Bay Resort in Hawaii, a place where Sarah had mentioned wanting to go. So it is not totally coincidental that upon Peter's arrival, he finds that Sarah is also there with her new boyfriend Aldous Snow, the pretentious lead singer for the band Infant Sorrow. Peter's plan of forgetting about Sarah is impossible, of which the staff and many of the guests at the hotel are aware, but neither Peter or Sarah refuse to let the other's presence at the resort make them run away. With the help of Brian, Brian's wife Liz and the hotel staff, Peter tries to move on with his life specifically with Rachel Jansen, one of the customer service agents at the hotel, who is carrying some emotional baggage of her own. But Peter goes into a further emotional tailspin when Sarah's life also takes a turn.