It was a bit of a false alarm, but everybody in the know realized that the invasion would have to begin in the next few weeks, before the start of the annual (and terrible) English Channel storms of late September.
With the expected fall of the aircraft carrier Britain, now all alone against the might of a loose coalition of Germany, Russia, Italy and Japan, these remain the darkest two weeks of the entire war for the cause of freedom and peace.
Dr Martin Henry Dawson had spent time, during his military service in WWI, hiking along the very short route the German tanks would take from Kent's sandy beaches to the southern suburbs of London.
He knew how it could be all over in a day or two's fighting.
Dawson was now too old to be effective at the fighting end of this war but his fighting spirit still hadn't left him.
Bu what on earth could a middle aged top notch medical researcher, albeit in the non-military area of chronic arthritis, actually do now to help the cause ?
As it happened, he had arrived back at his medical school the previous week to discover that the start of the new school year would see a shift out of resources for social medicine - helping the small and the weak 4Fs - to war medicine, to aiding the 1A military recruits.
It all was really just an excuse by those who had always opposed helping the needy of the small occupied countries of war torn Europe, to use 'war preparation' to also cut aid to America's needy.
Dawson was so worked up by both this homegrown hypocrisy and the evil efforts of Hitler abroad, that as often happens in cases of severe stress, he apparently made himself ill with an auto immune disease, then then usually fatal Myasthenia Gravis.
Dawson wasn't to realize this for a few more months. For now all he felt was very wan and very tired, which he put down to worry and lack of a good night's rest.
As it just happened, a German-born Jewish biochemist, Dr Karl Meyer, who Dawson was currently doing research with on the flesh eating powers of strep bacteria, had just proposed that Dawson help his efforts to synthesize an improved artificial version of a natural fungus mold extract.
Synthesizing this valuable medicine would be Meyer's contribution to the war effort.
Meyer wanted Dawson to grow industrial pilot plant levels (runs of 50 US gallons a time of liquid extract) of the fungus and by then test both the older natural and new artificial chemical to compare their anti-germ activity.
Dawson was very good at growing lab research levels of strep bacteria but regularly producing pilot plant levels of a common household mold inside a cleanliness-obsessed hospital was entire scientific and engineering universes away from his normal area of expertise !
But over the weekend, Dawson seemed to have read deeply into what little was known about this stuff, penicillin.
He saw that the natural penicillin already possessed an unique trio of characteristics that might allow him to finally conquer the Mount Everest of infectious diseases, SBE - subacute bacterial endocarditis, the disease that made Rheumatic Fever the leading killer of school age children.
Again, SBE was worlds away from his area of assigned expertise and in the protocol rigid confines of a world class hospital and medical school, filled with highly ambitious alpha male researchers, that really mattered.
Dawson had never shown any visible signs of interest in SBE, as a disease, to judge from the published records of him in journals and the minutes of medical conferences.
But the expected non-treatment of wartime SBEs, as a symbol of all that was wrong with the war against social medicine, their fate suddenly interested him muchly.
SBEs were seen as extremely costly in terms of hospital resources by those in the medical community long opposed to any form of social medicine and in a wartime resource crunch they were already arguing the SBEs should simply be abandoned to their dire fate.
It didn't help that, unlike Polio that mostly hit the white suburbs, Rheumatic Fever and SBE were mostly diseases of inner city kids - minorities, the poor, immigrants.
Dawson's brainwave was to put the biologically small (the penicillium) to work to save the lives of the human small down at the very bottom of the current human pecking order (the SBE patients).
His real target, beyond saving the lives of a handful of SBEs (all that was likely to come his way to treat) was people of good will and high morality, who were nevertheless sitting on their hands during the current moral crisis in Europe.
Traditional appeals to our moral obligation to help the weak and the small, the sort that had drawn in Dawson himself in WWI to help the suffering little Belgians, were clearly no longer working and hadn't worked since 1931 when the Japanese invaded Manchuria.
People of good will still sighed and worried as much as ever over the fate of the small suffering overseas.
But they did nothing - became mere bystanders, watching Axis bullies beat up the hapless.
Almost all felt hopeless to intervene, given the scant scientific understanding they had gained a half century earlier in public school.
Back then it seemed clear that Progress was directly aimed at evolving into the biggest, the strongest, might is right, bigger is better, God and Evolution is on the side of the biggest battalions etc.
One could wish it was different but the sad fate of the small is inevitable - it was natural.
But to Dawson, this "Appeal to Nature" fallacy was never more false.
Life is on the side of the small battalions
The current evidence, circa 1940, actually shown that the progress of both the Universe and the Earth was generally oriented, if oriented they be, to the small and the non-solid.
If he could but show the bystanders of good will that their outdated scientific understanding was totally wrong, that the small in biology and humanity still had useful roles to play, then perhaps the Bystanders' traditional feelings of empathy and charity could flow freely once again.
Of course, Dawson wanted to save all the lives he could, in the war zones and among the SBEs.
But I believe he was certain that his all-out efforts to save the SBEs, in a time of war priorities, would ultimately rouse such fierce opposition that there then would be a very public and heated debate over the true war aims of the Allies.
One set of war aims, Churchill's throughout the war, was to almost match the Nazis on a slippery moral slope ever downwards in order to 'quickly' defeat them, because this need for a speedy end justified using almost any means.
This approach focused on a military route to defeating Hitler, without altering in anyway the existing social system in the West.
The other - FDR's initially, though he later adopted Churchill's approach - was to defeat Hitler morally as well as militarily.
FDR and his team of advisors publicly proposed a new set of rules for humanity to live by (the Four Freedoms, the Atlantic Charter) that contrasted much more strongly with Hitler's ideology than did the existing practises of the western nations.
This second approach was exactly what Dawson was aiming at -- though he felt it had to move beyond high sounding rhetoric to real life practise.
For, despite FDR's soaring rhetoric of 1940-1941, the American medical elite's attitude to the SBEs in 1942-1945 was actually a slightly milder variant of Hitler's Aktion T4 : only here their death was to be by neglect, rather than death by needle or gas.
Thanks to Dawson, around the September 1943 very public life and death of young SBE Marie Barker of Chicago, the ordinary people of the western world finally had that serious conversation over the Allies' true war aims.....