Conor (Lewis MacDougall) is dealing with far more than other boys his age. His beloved and devoted mother (Felicity Jones) is ill. He has little in common with his imperious grandmother. His father has resettled thousands of miles away. But Conor finds a most unlikely ally when the Monster (Liam Neeson) appears at his bedroom window one night. Ancient, wild, and relentless, the Monster guides Conor on a journey of courage, faith, and truth as Conor faces one of the most difficult times in one's life while powerfully fusing imagination and reality.