Det är en referens till The Naked Time , som innehöll en tidigare epidemi av samma sjukdom på strängar av vattenmolekyler. Från transkription :
MCCOY: McCoy to Bio. We've isolated it. Start preparing serum.
HARRISON [OC]: What, Doctor?
MCCOY: It's water. Somehow on this planet, water's changed to a complex chain of molecules.
HARRISON [OC]: What's that, Doctor?
MCCOY: That's how we missed it. It passed from man to man through perspiration. Once in the bloodstream, it acts like alcohol, depresses the centres of judgment, self-control. Now get someone to the lab. Tell them the serum works, and start preparing more.