Pulse

Kristen Bell stars as Mattie, a student whose ex-boyfriend, Josh (Jonathan Tucker), goes through a strange transformation, then hangs himself. His depression seems to have emanated from a computer program he was working on--which continues running even when it's not plugged in. As they delve deeper into what happened to Josh, Mattie and her best friends, Isabell (Christina Milian), Stone (Rick Gonzalez), and Tim (Samm Levine), start seeing bizarre images that none of them can explain as more and more people around them are dying unexplainable deaths. With the help of Dexter (Ian Somerhalder), Mattie begins putting the details together, leading to a frightening and surprising conclusion. (official distributor synopsis)