After Courage sees a list of missing dogs, a flashback appears showing how Courage's parents got sent into outer space by an evil veterinarian. Muriel and Eustace take Courage to the same veterinarian to get him checked out. But the veterinarian plans to send Muriel and Eustace to outer space. Determined not to lose his owners like his parents, he must rescue them before they too suffer the same fate.
Eustace and Muriel never returned a book named "The Pixie and the Prickle Pirate," so they become characters in the book until Courage pays the fine. So Courage tries to find ways of gaining money, even making a performance of Eustace and Muriel as characters
Courage finds a two year overdue book. When he decides to return it, he does not have enough money for the $10,000 fee, so the librarian casts a spell on Muriel and Eustace, turning them into the characters from the book until Courage finds enough money to pay the fee for the book.
A pregnant space-faring squid who creates stars lands on the farm. Eustace plans to sell her eggs to the military for research. Courage has to save the eggs and the mother squid to keep the heavens twinkling.
Unimpressed by Jojo the Dolphin's performance at a local aquarium, Eustace challenges the sea mammal to a race, losing pathetically. He demands a rematch, staking his wife as the prize of the race.
Muriel refuses to talk after Eustace keeps ignoring her, so Shirley makes a giant starfish attack and it can only be stopped at the sound of Muriel's voice.
Muriel's "Uncle Angus" invites her to Scotland, where he imprisons her and demands that she makes thousands of kilts. It's up to Courage to learn Uncle's real name and free Muriel.