Siren Phillips has lived her life thinking she's an ordinary girl, in an ordinary town. On the eve of her twelfth birthday, however, she learns that she is far from ordinary. Destined to turn into a Mermaid at the age of twelve, Siren must struggle with her new reality, saying good bye to her mother and friends, while she transitions into the water. To make matters worse, a group of Hunters are after her, trying to catch her. She soon becomes friends with Adam Wilts, a new boy at school, who she turns to for help. He agrees to help her, but finds himself caught in the middle, when it's his own father who is after Siren. When Siren's mother is taken, the town must rally behind her, and help her make a peaceful transition into the water, before the hunters can find out where she is.

An adopted Irish American artist confronts her past when both sets of parents come together over a weekend for her to paint a family portrait.

The screenplay centers on characters Brendan Young and Darryl Jennings who take a trip to the Lake Arrowhead with a group of college friends to celebrate Young's girlfriend's birthday. One-by-one the coeds begin disappearing until a mysterious young visitor arrives and helps them begin to unravel their tangled web of terror.

A sailor prone to violent outbursts is sent to a naval psychiatrist for help. Refusing at first to open up, the young man eventually breaks down and reveals a horrific childhood. Through the guidance of his doctor, he confronts his painful past and begins a quest to find the family he never knew.