When their eldest brother dies, Peter and Alice seek to save their parents from despair until they are forced to choose between home and imagination, setting the stage for their iconic journeys into Wonderland and Neverland.

Eight-year-old Alice (Keira Chansa), her mischievous brother Peter (Jordan A. Nash) and their brilliant older sibling David (Reece Yates) let their imaginations run wild one blissful summer in the English countryside. Encouraged by their parents Jack and Rose (David Oyelowo and Angelina Jolie), the kids' make-believe tea parties, sword fights and pirate ship adventures come to an abrupt end when tragedy strikes. Peter, eager to prove himself a hero to his grief-stricken and financially-struggling parents, journeys with Alice to London, where they try to sell a treasured heirloom to the sinister pawnshop owner known as C.J. (David Gyasi). Returning home, Alice seeks temporary refuge in a wondrous rabbit hole while Peter permanently escapes reality by entering a magical realm as leader of the "Lost Boys."