Kevin McCallister was mad at his entire family for always treating him badly and bullying and abusing him emotionally, verbally and psychologically and never getting punished or feeling bad for it yet Kevin always being the one getting punished for reacting the right way.
Kevin has gotten sick of his family's treatment of him, he wants it to stop... And he is about to do something about it.
Meanwhile Henry Evans, Kevin's psychopathic doppelganger has just been presumed dead by his family after falling off a cliff into the ocean after trying to kill both his mother and cousin for no good reason. Little do the Evans know that Henry is still alive and wanting revenge but he will need help to get it.
Kevin's family has just travelled to paris without him as he wished his family would disappear which means Kevin is at home all alone, as Kevin joyfully roams the house and vandalizes Buzz's room and Yells "Hey Buzz i'm in your room looking at your stuff, you better come and stop me"!. Kevin hated Buzz the most out of his entire family and Uncle Frank since they were the meanest to him as Buzz ate Kevins piece of pizza and mocked him about and Uncle Frank yelled at him and called him a little jerk and nobody even called him out on it as if everything that happened was Kevin's fault.
Then Kevins bad mother put Kevin in his room even though he told her what Buzz did but she said "You're the one who is acting up" and nobody else was in trouble or even lectured for their bad behaviour. But now Kevin was home alone without his family to degrade and oppress him. Kevin then watches the R rated movie his family told him not to watch and although he is scared he also enjoys the movie.
Later Kevin happily buys stuff from the store and overcomes his fear of the heater in the basement, while he is also being stalked by the wet bandits who want to burgle his house.