As the family drives home from the water-park, they get stuck in a traffic jam. While each family members tries to deal with heat, stress and boredom in their own way, Dewey is roaming the country on his own.
On the way home from the water park, the family get stuck in a traffic jam after a car crash; During the jam, Malcolm meets a girl, Reese declares war on an ice cream truck, Lois gets frustrated, and Hal is in shock when he realizes he could've been the one in the car crash.