In a near future, crimes and accidents can be prevented by making just one phone call to the past. However, the peace of this utopian world will be disrupted by a methodical killer who seems to have discovered the only flaw in this system.

In a near future, crimes and accidents can be prevented by making just one phone call to the past. However, the peace of this utopian world will be disrupted by a methodical killer who seems to have discovered the only flaw in this system.