Onleaveinashoresidetown,Johnnybecomesinterestedinayoungdarkhairedwoman.Theymeetandhelearnsthatsheplaysamermaidinthelocalcarnival.Afterstrangeoccurrences,Johnnybeginstobelievethatshemayactuallybearealmermaidthathabituallykillsduringthecycleofthefullmoon.