After waking from a three-year vegetative coma, Song Linglong finds the familiar world utterly unrecognizable. Residents of her apartment complex sleepwalk collectively like marionettes every midnight. Everyone warns her that people around her have been replaced by inhuman entities. Determined to uncover the truth, she is forced to venture into a horrifying nest teeming with writhing mycelium where individual minds merge into one, a place all clues compel her to seek out.