As the result of the curse of a once-beautiful witch (Meryl Streep), a baker (James Corden) and his wife (Emily Blunt) are childless. Three days before the rise of a blue moon, they venture into the forest to find the ingredients that will reverse the spell and restore the witch's beauty: a milk-white cow, hair as yellow as corn, a blood-red cape, and a slipper of gold. During their journey, they meet Cinderella, Little Red Riding Hood, Rapunzel and Jack, each one on a quest to fulfill a wish.

Gum stuck in his hair signals the start of a disastrous day for 11-year-old Alexander (Ed Oxenbould). One calamity follows another, but when Alexander tells his family about his misadventures, he finds little sympathy. Alexander begins to wonder if bad things happen only to him, but he soon learns that he's not alone when his mother (Jennifer Garner), father (Steve Carell), brother (Dylan Minnette) and sister (Kerris Dorsey) all find themselves living through their own calamitous days.