The boys explore as children will and find their grandfather is harboring a large turtle-like creature called Mel.
Mel is a legend of local Swanson Lake and is known as Swannie to the general populace (similar to "Nessie").
While going around with a girl (Susie) one day, Roger (the elder boy) accidentally causes an explosion on the developer's property with his grandfather's tractor.
The boys end up staging a break out for Mel from the amusement park and with the help of Susie and her brother try to get him back to the lake, setting a tiger loose and creating mayhem in the process.
"[4] A review at Teen Ink was also appreciative of the film, "This is a movie that needs open minded people.