Kate and her older brother Brandon are moving back to their old hometown after six years. On the night he graduated from high school Brandon had a fight with his girlfriend Lucinda over flirting with other people. Lucinda threatened to go to her “special place” and he turned his back on her. Kate saw something weird in the lake and no one saw Lucinda again.
Lucinda’s little brother Keith sent back a newspaper clipping, showing that the lake in town was drying up. At one point, the town moved all of its buildings and flooded the area, creating the lake. Brandon moves them back and asks Keith about Lucinda. Keith claims that no one has found anything except for an old graduation robe.
They run into his old friend Holly who is excited to see him. Kate mentions that she wrote him a ton of letters, but he never wrote her back. Holly explains that she feels responsible because Lucinda wasn’t happy about her relationship with Brandon. She also believes that Lucinda ran away from home and just never contacted anyone.
The first night back Kate hears weird noises. She wakes up and finds a puddle of water in her room. She follows the water drops back to the old lake and sees a big wet spot on the house where Lucinda and her family once lived. When she goes home, Brandon is clutching an old graduation robe that he found on the back porch. He is convinced that she left it there as a sign.
Kate goes to Keith’s house and asks to see photos of their old house. She notices a pipe coming out of the basement and remembers his mom telling them that it was venting for an old crawlspace. She goes back to the lake that night and finds the house. Kate spots stairs leading down to the basement and follows them.
She hears a noise, looks up and sees a woman in a red graduation robe. Thinking it’s Lucinda, she calls out and the figure jumps into the basement. The woman attacks her, they fight and she pushes Kate further into the basement. The figure opens a hidden door, shoves her inside and Kate comes face to face with the real body of Lucinda.
Kate pushes her off and when she turns around, she sees Holly. Holly was an expert scuba diver and the group of them frequently dived in the old lake. When Lucinda stormed off, she went to her “special place”, which was the old storm cellar/crawlspace. They fought and Holly shoved her inside, took her equipment and left her. She explains that she knew Brandon would eventually go back to Lucinda.
Keith shows up and helps her subdue Holly until the police arrive. The next morning Kate finds a bouquet of flowers in her room next to a puddle of water, one last sign from Lucinda.