Ok so I'm basically always thinking about this fic from @rokhal and upon my mandatory bi-weekly re read a nuron managed to fire.
Thinking maybe Robbie still hasn't given up on trying to find a cure for what he and Gabe have and remembers the reaction he first had to the antifungal medication he got. Figures maybe he's built up a resistance or something and thinks 'what if I take a more DIRECT route?'
So he brakes open a pill and spreads its contents on a little plate. Makes a small cut on his hand and lets his weird kinda sorta blood drip onto it.
The effect is immediate. The fungi sort of bubbles and then expands like it's trying to get away, then calcifies and crumbles till there's nothing left.
Idk if he would actually be willing to test Gabes blood. I think their trust is a little warbly to put it lightly. But if he did, Gabes blood would still stay normal for a second and then have the same reaction. Gabe isn't made of The Mold like Robbie is, but he's still so thoroughly infected that trying to take a cure would probably kill him.

















