[P]
A combination of two different yeast complexes?
Pasteurization? $$$$$$
https://en.wikipedia.org/wiki/Saccharomyces_pastorianus
https://en.wikipedia.org/wiki/Louis_Pasteur
https://en.wikipedia.org/wiki/Pasteur_Institute_of_Lille
https://en.wikipedia.org/wiki/Pasteur_Institute
This is most definitely the keystone. Read through that article on the Pasteur Institute. They practically invented fucking around with viruses and disease pandemics. Maybe they know the forgotten combination and sources of the yeast.
Multiple meanings.
https://www.atlasobscura.com/places/dupont-underground
Why is there no metro in Georgetown???
https://www.atlasobscura.com/places/university-of-virginia-7-z-rotunda-secret-society
Donations have been known to come in for amounts like $17,777.77, delivered at fundraising events by a student in the seventh seat of the seventh row. Any communications to and from the group are generally left at the base of the Jefferson statue in the Rotunda or in the crook of its arm, and letters are traditionally signed with seven astronomical symbols.