Stranded on a secluded tropical island after a violent night storm, Elias and Maya stumble upon a hidden lagoon and the enigmatic siren, Calista. Charming, alluring, and impossible to read, the mermaid draws them into a strange game of curiosity, attraction, and subtle manipulation as she offers to show them a world hidden beneath the waves. As the boundaries between friendship, romance, and jealousy begin to blur, neither tourist can be certain whether Calista is bringing them closer together—or quietly pulling them apart.