Scientists at an observatory take photographic plates of a mysterious celestial object near Mars using a highly sophisticated telescope and determine it is a cloud of some sort. The cloud soon permeates the planet's atmosphere. Although Earth is only enveloped in its mass for a day before it moves on, the organic polymers start having an unusual effect on the environment.
Meanwhile, oceanographer Dr. Sam Brooks and his colleague Dr. Charlie Frazier along with a science reporter named Carl Loudermilch are out on the ocean collecting samples of seawater for analysis when they discover that the cloud is increasing water viscosity somehow. All water on Earth is slowly taking on a consistency roughly akin to gel. With nothing to drink, no rain, no water to irrigate crops and the oceans slowly solidifying into a viscous glop, Brooks, Frazier and Loudermilch, along with wealthy yacht owners Hugh Winthrop and Gail Cooper, stranded in the ocean, have to figure out a means of reversing the cloud's effects as order begins to break down around the world with Earth facing a potentially apocalyptic global drought.
This novel was Thomas and Wilhelm's second collaboration following the Blob Monster story The Clone. The paperback edition was published by Playboy Press, one of Playboy's more "legitimate" enterprises.
Tropes used in this novel:
- Apocalypse How: Class 4-5 Planetary Total Extinction of everything that requires water to survive unless the heroes find a way to turn the water back to normal. They succeed, so the novel concludes with, at worst, a Class 1 Planetary Societal Disruption.
- Closed Circle: Due to the ocean taking on the consistency of rubber cement, the characters end up stranded at sea aboared their ship, unable to return to port, completely cut off from civilization.
- Cosmic Horror Story: Of a sort. The cloud isn't a living organism with any agency, but there's nothing like a faceless, uncaring celestial phenomenon we can barely comprehend and whose effects upon our planet are utterly devastating to make mankind feel insignificant and powerless. In fact, considering that Brooks and co. manages to undo the effects of the cloud and return Earth's water to normal, one could argue that The Year of the Cloud is Thomas and Wilhelm's middle finger to the very idea of Cosmic Horror; humanity may be insignificant but it isn't powerless.
- Cozy Catastrophe: Much of the story is spent aboard the private yacht, which is stuck at sea in the solidified water, with the characters getting drunk on the ship's prodigious supply of ritzy booze. This kind of takes the urgency out of Brooks' efforts to find a means of reversing the cloud's effects, robbing the story of some of its tension.
- Not So Harmless: The cloud and what it does. The world's water turning into Jell-O may seem silly at first, but then your remember that solid water which cannot be melted into liquid form means no rain, meaning a potentially world-ending drought.
- What the Hell Is That Accent?: Dr. Yudkin is American, but because he thinks Americans expect smart people to have a foreign accent of some sort, he puts on a phony accent of indeterminate, vaguely "European" origin.