The Pulse is depicted as an electrical signal that simultaneously transmitted globally through cellular telephones in roughly 2006. Everyone using a cellphone at the time of the Pulse experienced a kind of psychological "reboot," with the following initial effects:
- Hostility- Phoners, as they later came to be called, immediately began attacking everyone else they could see or hear. Mass chaos resulted as Phoners recklessly tried to murder everyone in sight. They attacked animals, too, and were at first as hostile to each other as they were to people unaffected by the Pulse.
- Suicidal Behavior- Phoners went on an instant rampage, doing things that would be likely or guaranteed to get them severely injured or killed. Some, as far as can be determined, deliberately killed themselves right after the Pulse hit them. One girl ran into a streetlamp pole face-first several times, smashing her teeth in, inflicting self-injury that would inevitably kill her without medical attention (due to blood loss or bacterial infection). Massive explosions occur several times around Boston, implied to be because of Phoners helping to crash aircraft in flight and cars on the road.
- Psychological Reboot: Phoners had their minds essentially erased on the spot the instant the Pulse hit them. Alice Maxwell's mother turned on her like a savage animal, and Alice described her as completely failing to recognize her own daughter. Phoners held no memory of who or what they had once been and their minds were at best severely damaged. Even "second-hand" exposure to the Pulse, such as listening in closely to a cell phone call a friend is taking, was enough to do serious mental harm.