The people of Lakeport have seen something big and green with sharp teeth roaming the forest, and the Bobbsey twins are determined to get to the bottom of this mystery. Could a dinosaur really be living in their forest?
Strange sounds are coming from the attic, and the Bobbsey Twins are sure it must be a ghost. When Mom and Dad don't believe their story, it's up to Freddie and Flossie to solve the mystery.