April 12th,1944  With 'Operation Overlord' to commence in a couple of months why not have Hitler move more forces towards Calais. There had been enough intelligence that this was the Fuehrer's thinking the attack would come there. It was the nearest point and German Air recon knew the massive shipping in England indicated the attack was a month or 2 at most. Erwin Rommel had stated He believed it would be during early June though Hitler disagreed on Rommels choice of Normandy. So the Eighth Army Air Force would stop scattering for a week or two and bomb Calais relentless. During the attack a Russian underground group would aid and a few Brit Paratroops would also drop in to suprise the Huns, then both slip back into the Shadows after doing what they could.
