Iguanis of the Iguana Men orders two of his men to capture Tom and Tubb. They are very aware that Moby is their guardian and set a trap to capture them. Scooby alerts Moby that the boys have been captured so he chases after the Iguana Men to try to save his friends. The Iguana Men fire exploding underwater mines at Moby to slow him down. Iguanis plans to experiment on the boys so that he can transfer their ability to breathe above water to his trained Sea Terrors and take over the world. Moby is able to find the location of the boys and fights to get them free. The boys escape the laboratory using the ship they were captured in. Iguanis sends his Sea Terrors after Moby and the boys, but Moby is able to defeat them and destroy the laboratory.