Struggling musician Peter Bretter (Jason Segel) has spent six years idolizing his girlfriend, television star Sarah Marshall (Kristen Bell). He's the guy left holding her purse in paparazzi photos and accidentally omitted from acceptance award speeches. But his world is rocked when she dumps him and Peter finds himself alone. After an unsuccessful bout of womanizing and an on-the-job nervous breakdown, he sees that not having Sarah may just ruin...