The film begins with a sleepover of children prank calling people playing the game Seventy Five while their parents are in the other room having drinks. The rules of the game are that you must keep some random person on the line for 75 seconds, and they must believe what you’re saying. As the night goes on the kids go to bed, a man whom the kids recently called calls back, before jumping from a closet and killing all the parents in the house with an axe as the children hide in their bedrooms.

Ten years later, a man is masturbating in his house, when he receives a phone call from someone telling him they can see him. He begins to walk slowly through the house, before hanging up the phone, assuming it’s a prank call. He resumes his activities at his computer before a man appears behind him, killing him with an axe.

Meanwhile, a group of college students are preparing to go to a party in an obscure mansion a few hours away. On their way to the mansion, they stop at a gas station to use the restroom, and the news of the murder is reported on the television. It is revealed that the man who died was one of the children from the original Waley murders at the beginning of the story.

Two detectives are called in to help solve the case. They track down another survivor of the murders, only to find her and her boyfriend dead at her trailer. They go onto another college where another child lives, only to find them dead as well. It is then revealed that two of the students at the party were also orphaned at the murder.

Back at the mansion, the party starts, with Marcus suggesting a game of Seventy Five. At first it’s all going well, until one guest pretends he is in someones house, about to kill them. The tables are turned when the person they called reveals they are a murderer, and proceeds to kill someone while on the phone. They all agree not to answer the phone again that night, but one girl does anyway, giving directions to the pizza boy. However, when two guys look around, they realize the pizza is already delivered.