Steve McQueen’s “Blitz” follows the epic journey of George (Elliott Heffernan), a 9-year-old boy in London during World War II, whose mother Rita (Saoirse Ronan) sends him to safety in the English countryside. George, rebellious and determined to return home to his mother and grandfather Gerald (Paul Weller) in East London, sets off on an adventure only to find himself in great danger, while a distraught Rita searches for her missing son.