Bank clerk Stanley Ipkiss is transformed into a manic superhero when he wears a mysterious mask.

In the summer of 1989, a group of bullied kids band together to destroy a shape-shifting monster, which disguises itself as a clown and preys on the children of Derry, their small Maine town.

When timid bank clerk Stanley Ipkiss discovers a magical mask containing the spirit of the Norse god Loki, his entire life changes. While wearing the mask, Ipkiss becomes a supernatural playboy exuding charm and confidence which allows him to catch the eye of local nightclub singer Tina Carlyle. Unfortunately, under the mask's influence, Ipkiss also robs a bank, which angers junior crime lord Dorian Tyrell, whose goons get blamed for the heist.