Lone Starr and Barf are named fans of the day at a Spankees ball game and win a trip to Watch your Assic Park to see the Spankees train. After they arrive at Isla Nueblo (180 star miles from Planet Costa Rica) they learn how Skroob, the owner of the Spankees, uses a combination of steroids and dinosaur DNA to create Dino-athletes and rule the sports universe. Despite being quite disgusted, Lone Starr, Barf, Vespa and Dot take the park tour anyway, accompanied by Skroob's precocious 9 year old niece Jasmine and two anonymous lawyers.

Lone Starr sells some of his organs so he can buy a brand new van. President Scroob catapults a mighty meteor towards Druidia, which attracts other cataclysms in it's wake.