RAF Spitfires locate the Luftwaffe bomber formation they have been vectored to intercept: Heinkel He IIIs in strength with close protection from twin-engined Messerschmitt Bf 110 heavy fighters. Hugely outnumbered as usual during the Battle of Britain, the Spitfires pounce from above - and will have to watch their sixes for more dangerous Bf 109s flying top cover.