When Molly and Gil found a crystal on the ground beside the post centre in Bubbletucky they thought it was an ordinary crystal but when they touched it they felt a bit strange the crystal made them turn into Humans with legs but when the crystal became malfunctioned they can't turn them back into guppies so all of the guppies had to help them find a way to change them back into guppies again but when there was a crime at school and took the crystal Molly and Gil had to use the legs to catch the thieves who took the crystal will they get back the crystal and turn them back into guppies again before it's too late?
