The first sequel is titled PULSE: AFTERLIFEThe world has been reshaped by the invasion of ghosts via the wireless internet. Cities are deserted, technology has been destroyed and the few remaining human beings eschew anything electrical in order to avoid a confrontation with the soulless ghosts that now wander the planet. Most of the ghosts are doomed to a repetitive loop of something they did while they were still despairing humans (a man repeatedly hangs himself, for example), but there are some ghosts so locked in denial, they do not know they are dead. They continue to haunt their homes, wrapped in fear that their souls will soon be torn from them.The second sequel is titled PULSE: INVASIONIt is now seven years later and the survivors on Earth have settled into a primitive lifestyle completely void of electronics. The clusters of human survivors live together in refugee camps as the phantoms have taken over the cities. Justine is now a teenager and she escapes to the city to try and make a life for herself where she is not a drain on her adopted family (her parents both became phantoms in part one). She heads in to the city at the urging of Adam, a seeming survivor in the city that lures her with promises of understanding and friendship.- Wikipedia
How do the ghosts invade the world?
wireless internet