After July 20th, 1944 plot failed miserably (and predictably – Wehrmacht generals were no putschists and neither were the civilian members of anti-Nazi resistance), it became painfully obvious to Heinrich Himmler that his chances of ever replacing Adolf Hitler as Der Führer (and thus of making peace with Western Allies) are exactly those of a snowball in Hell (if not lower).
Hence, he was left with but three options – die heroically in hopeless battle take his own life or have his life taken from him by a British, American or Soviet hangman (after a humiliating trial). If he makes it to the trial, of course – with his resume even this deadly outcome was obviously not guaranteed.
The obvious alternative to these unhealthy options was to escape from Nazi Germany… somewhere and start there a new life (i.e. on a chicken farm which he initially planned to have).
There were, however, several seemingly insurmountable obstacles. First, it was necessary to somehow prepare this escape – and to it clandestinely, because had Adolf Hitler got even a hint of such preparations, Himmler would have been immediately arrested, tried and hung as a traitor on a piano wire (the standards method of capital punishment for traitors in Nazi Germany).
And as he had a lot of powerful enemies in the Reich, the chances of Hitler being informed about these attempts, were significant. Especially given the fact that Himmler did not need enemies for this to happen.
Unlike Himmler (and Heydrich), just about all SS members (including those in Himmler’s inner circle), worshipped Hitler like a demi-God. And thus (at least in summer of 1944) were completely confident that he would (again) perform a miracle, save the Third Reich and win the war. Consequently, for them the very idea of planning an escape from Nazi Germany during the war was… well, treason.
Besides, Himmler had simply way too much on his plate to devote the necessary time and effort to engineer his escape. In addition to being the SS-Reichsfuhrer, he was now the Minister of the Interior, Reichsleiter, Reich Commissioner for the Consolidation of German Nationhood… and from July 21st, 1944 (i.e., the next day after the failed coup) the Commander of the Replacement Army.
Consequently, he had no time to plan and engineer his escape… and no one trustworthy and capable to task with this genuinely existential endeavor. So the situation seemed all but hopeless.
And then, sometime in very late July – or in a very early August – the agents of The Black Sun Society showed up on his doorsteps. Dressed, most likely, in the impeccable feldgrau of the SS.