Dr Newman, Host and others in “Unfinished Business”

[notices audience murmuring] Yes, that’s the usual response. Fungi seem harmless enough. Many species know otherwise. Because there are some fungi who seek not to kill, but to control. Let me ask you, where do we get LSD from?

Where do you get it from? [audience laughs]

It comes from ergot, a fungus. Psilocybin? Also a fungus. Viruses can make us ill, but fungi can alter our very minds. There’s a fungus that infects insects. Gets inside an ant, for example, travels through its circulatory system to the ant’s brain and then floods it with hallucinogens, thus bending the ant’s mind to its will. The fungus starts to direct the ant’s behavior, telling it where to go, what to do, like a puppeteer with a marionette. And it gets worse. The fungus needs food to live, so it begins to devour its host from within, replacing the ant’s flesh with its own, but it doesn’t let its victim die. No, it... it keeps its puppet alive by preventing decomposition. How? Where do we get penicillin from?

Fungus? [points at host]

Oh..

Dr. Schoenheist, you’re in distress.

Fungal infection of this kind is real, but not in humans.

True, fungi cannot survive if its host’s internal temperature is over 94 degrees. And currently, there are no reasons for fungi to evolve to be able to withstand higher temperatures. But what if that were to change? What if, for instance, the world were to get slightly warmer? Well, now there is reason to evolve. One gene mutates and an Ascomycota, uh, candida, ergot, cordyceps, aspergillus, any one of them could become capable of burrowing into our brains and taking control not of millions of us, but billions of us. Billions of puppets with poisoned minds permanently fixed on one unifying goal: to spread the infection to every last human alive by any means necessary. And there are no treatments for this. No preventatives, no cures. They don’t exist. It’s not even possible to make them.

So if that happens?

We lose.