The Mandela Effect

A man becomes obsessed with facts and events that have been collectively misremembered by thousands of people, believing they are symptoms of a larger issue. He eventually concludes that these discrepancies are due to shifts between parallel universes and sets out to develop a program that could interrupt the simulation. His obsession takes a toll on his mental health and marriage, leading him to question reality itself in a desperate bid to save the life of his daughter, who he is convinced still exists in one of these parallel realities.