Steve McQueen’s “Blitz” follows the epic journey of 9-year-old George (Elliott Heffernan), a boy who finds himself in World War II London and is sent to safety by his mother, Rita (Saoirse Ronan), in the English countryside. Defiant and determined to return home to his mother and grandfather Gerald (Paul Weller) in East London, George embarks on an adventure but finds himself in immense danger, while a distraught Rita searches for her missing son.