A different view: a chemical reaction requires two or more chemical substances or elements which interact with each other and an optional
catalyst. I concur that this might mean that
Tanya and
Kelly will synthesize more knowledge about what caused z-day, they might even be able to create some sort of antidote "foo". Sincerely, I do not regard this to be very likely. My guess is that the next episode will leave the comfort zone.
Burt and
Riley will probably find the first clues which point at
Scratch's actions during the last couple of days. Moreover, the
Dunbar appartement building might become a really unpleasant place soon...
As mentioned before by
others, the water reserve of
the colony could be a possible target as well. Damn.