Pulse Movie Wiki

Mattie and her friends begin to receive online messages from Josh asking for help but assume that Josh's computer is still on and that a virus is creating the messages. Mattie learns that Josh's computer has been sold to Dex McCarthy, who finds a number of strange videos on the computer. Mattie receives a package that Josh mailed two days prior to his death. Inside are rolls of red tape and a message telling her that the tape keeps "them" out, although he does not know why. Later, Dex visits Mattie and shows her video messages Josh was sending to Ziegler. Josh had hacked Ziegler's computer system and then distributed a virus. This virus had unlocked a portal that connected the realm of the living to the realm of the dead. Josh believed he had coded a counter to the virus and wanted to meet Ziegler at the library. Josh's counter-program is found on a memory stick taped inside the PC case with red tape.
Dex and Mattie visit Zeigler and find his room entirely plastered in red tape. They believe the red tape keeps the spirits out. Zeigler tells them of a project he worked on where he found "frequencies no one knew existed." Opening these frequencies somehow allowed the spirits to travel to the world of the living. Zeigler also tells them that these spirits "take away your will to live" and where to find the main server infected with the virus.