The kids from Mystery, Inc. are about to receive their highest honor yet... a lifetime achievement award from the Coolsonian Museum! The whole town of Coolsville has turned out to thank the gang for unmasking so many scary monsters. But -- ruh-roh -- in the middle of the awards ceremony, Scooby and Shaggy accidentally set all the monsters free again! Now all of Coolsville hates them. Worse, the gang has got to capture all the monsters they've ever faced... at the same time!