Greg Heffley tells about his summer vacation and his attempts to steer clear of trouble when he returns to middle school and tries to keep his older brother Rodrick from telling everyone about Greg's most humiliating experience of the summer.

The Heffley family road trip starts off full of promise, then quickly takes several wrong turns--with everything from a fender bender to crazed seagulls--but even the worst road trip can turn into an adventure, and this is one the Heffleys will not soon forget.