S1, E2: By May 1940 The Die Was Cast And The War Started In Earnest This Episode Examines The Buildup To The Battle Of Britain Studying The Technological Advances That The Raf Pioneered To The Start Of The Battle Itself At The Heart Of The Raf Production Were Two Worldclass Fighters The Hurricane And The Spitfire Which Could Compete Against The Best The Luftwaffe Had To Offer