It's a summer weekend in a country house near Sintra, in Portugal. Fourteen-year-old Nicolau is spending a couple of days with his older brother Simão and his friends, all of them in their late twenties. Everyone is drawn to the beautiful and quiet Maria do Mar, but Nicolau will see his life the most deeply shaken by her. Between homework and tree-climbing, stories about a deceased philandering grandfather and the origins of the tortellini's shape, a friend in a costume nursing a broken heart and seduction games, Nicolau observes this group of young adults.
Bound by a shared destiny, a bright, optimistic teen bursting with scientific curiosity and a former boy-genius inventor jaded by disillusionment embark on a danger-filled mission to unearth the secrets of an enigmatic place somewhere in time and space that exists in their collective memory as "Tomorrowland.