Solstice (2007)

Teenager Megan (Elisabeth Harnois), still distraught over her twin sister Sophie's suicide, reluctantly agrees to join her friends on a summer trip to a lake house in the bayous of Louisiana. On the way, at a gas station, they meet Nick (Tyler Hoechlin), who provides the group with information on voodoo and other local superstitions.

As soon as they arrive at the house, Megan suspects Sophie is trying to communicate with her, as a solstice — the time when our world and the next are closest — approaches. Megan goes running and trips, splitting her nail (something she had foreseen in several nightmares). As she limps back to the house, she meets a suspicious local resident, Leonard (R. Lee Ermey); inside his pickup truck, she finds a hat identical to one Sophie had owned.

The night before the solstice, Nick joins the group at the house for dinner. Megan tells him about Sophie's key chain, something she is trying to get rid of but it keeps returning, and that she thinks she is being haunted by Sophie's lost ghost. The six of them later go swimming and Nick calls for any spirits with wine; Megan is dragged under the water. Megan then, advised by Nick, wraps the key chain in a white cloth and buries it outside, which he says should expel the spirit. She goes for a bath, finding mud running out of the taps, and then sees the key chain lying on the floor.

The following day, Megan goes to Leonard's house and, inside, finds a young girl's bedroom (presumably his daughter); newspaper cuttings explain a young girl called Malin disappeared from the town a year earlier. Megan realises she is being haunted by Malin, not Sophie. Megan takes Nick to where she tripped on her run, followed by the group of friends, including Christian (Shawn Ashmore) who brings a gun. Nick and Megan get split up, and Christian almost shoots Nick. Megan then digs up Malin's body and finds that the key on the key chain is for Malin's bicycle, which was buried with her. They call the local police.

Christian finally admits that the year before, when they all came to the lake house without Megan, he and Sophie were on a drive and accidentally hit Malin. In fear of being arrested, they buried her in the forest, and Sophie later committed suicide as she could not bear the guilt. Malin's ghost appears, and Christian runs away towards the road. Megan chases him through the forest but before she can reach him, he is hit by the police car that had been called out.

The ending shows Megan at Malin's grave. When Leonard arrives home, he finds Malin's key chain on the porch, put there by Megan. Megan and Nick decide to go to the city to start a life together.