The Iron Cross Army are sabotaging oil-tankers with the help of their monster, the Sea-Devil, a semi-mechanical anthropomorphic swordfish with an ability to shoot torpedoes from its mouth. Spider-Man employs the help of the interpol agent Jūzō Mamiya to help him stop the Iron Cross Army. Spider-Man uses his remote controlled Marveller to prevent the Sea-Devil from bombing an industrial complex by making its missiles explode in the air. After that the monster's master makes it grow giant and Spider-Man has to use his Marveller to transform into a giant mech to fight the monster, after they exchange blows Spider-Man uses the mechs giant sword to disintegrate the Sea-Devil.
