AllMovie

Chapter nine of Republic's S.O.S. Coast Guard reveals that Officer Terry Kent (Ralph Byrd) and his two passengers, reporter Jean Norman (Maxine Doyle) and photographer Snapper McGee (Lee Ford), all managed to escape before their vehicle plunged into the ravine. Realizing that the game is up and that Terry is now in possession of evidence linking the kelp plant to the manufacture of disintegration gas, Boroff (Bela Lugosi) orders his men to mine the factory. The coast guard raids the plant but Terry arrives just in time to get all the men out. Unfortunately, despite warnings to stay put, Jean and Snapper wander into harms way just as the kelp factory explodes.