A young sailor falls in love with a mysterious woman performing as a mermaid on the local pier. As they become entwined, he comes to suspect the woman might be a real mermaid who lures men to a watery death during the full moon.
| Actor | Role |
|---|---|
 Dennis HopperJohnny Drake | Johnny Drake |
 Linda LawsonMora | Mora |
 Gavin MuirCapt. Samuel Murdock | Capt. Samuel Murdock |
 Luana AndersEllen Sands | Ellen Sands |
 Marjorie EatonMadame Romanovitch | Madame Romanovitch |
 Tom DillonMerry-Go-Round Operator | Merry-Go-Round Operator |
| HH.E. WestLt. Henderson | Lt. Henderson |
 Marjorie CameronWater Witch | Water Witch |
| CChainoHead Bongo Player | Head Bongo Player |
| KKirby AllanBongo player | Bongo player |
| BBarbetteMan Talking at Bar | Man Talking at Bar |
| DDanny BestTeen on Midway | Teen on Midway |
| JJames BosconTeen on Midway Gawking at Mermaid | Teen on Midway Gawking at Mermaid |
| RRichard BosconTeen on Midway with Glasses | Teen on Midway with Glasses |
| PPaul HornJazz Flutist | Jazz Flutist |
| JJoyce KingWoman at Jazz Club | Woman at Jazz Club |
 Bruno VeSotaMan on the stairs | Man on the stairs |