I’ll try to avoid spoilers here, which will keep the plot description short.
Jasper Fforde is an exceptional author famous for the “Thursday Next” series and presented here already with his novel “Shades of Grey” (not to be confused with “50 Shades of Grey”). One other novel of his I want to talk about is “Early Riser”, set not only in an alternate history, but a whole alternate biosphere, where the Ice Age never went away and so history is different, technology developed somewhat differently, and humankind evolved differently – it hibernates during winter.

Hibernation is no game: if you wake up too early you may die due to neural collapse, and even asleep danger awaits in the form of malnutrition, freezing, carbon dioxide buildup, and whatnot. To support the population during their winter sleep, Britain has the Winter Consul Service, an organization of oddballs whose job it is to stay awake during the cold season and keep the sleepers safe, and civilization running.

The main character is one Charlie Worthing who never fit in well in normal society, is even actively disliked by many, not least because of a somewhat malformed head and face. So what better way to get a reprieve from judgemental stares and off-tellings than to join the Winter Consuls! Here Charlie hopes to learn the trade from an old hand, a seasoned and celebrated veteran, but then, as you can imagine, everything goes off the rails rather hard and fast and Charlie has to rely on instinct to make the right choices.

Turns out that national sleepy-time is not all that quiet and peaceful at all: there is all sorts of shenanigans going on among those who stay awake for one reason or another, and apart from the Winter Consuls there are private companies engaging in corporate espionage while most of the staff is asleep, ne’er-do-wells trying to profit during the cold and lonely winters, and really weird people, like one woman who lives two lives, excels in two careers, and is her own worst enemy.

And then there is one particular threat that may endanger every sleeper’s sanity and life: a viral dream that start spreading like a disease, inserting itself into the dreamspaces of whole hives of hibernaters, and wouldn’t you know it, the outlandish backwater sector where Charlie is posted turns out to be the very hotspot of viral dreaming, where shady people are ready to kill for their goals centered around that odd, shared dream.

Worldbuilding

We know from other works of Jasper Fforde that he likes the weird and odd, and doesn’t play inside the usual boundaries. In classic Fforde fashion, this strange world is presented as simple facts, with details simply skimmed over as if they were general knowledge, although the most important concepts are explained in footnotes. In a way we are eased into the cold water due to Charlie being a novice, so we learn the ropes of winter-time through Charlie’s eyes. Still, the book demands full acceptance from the reader: if something seems strange, just accept it and go along with it… that’s the best way to have it all make sense going forward.

In Shades of Grey, Worldbuilding was front and center, and the main character was mostly just our window into that world.
Early Riser places more emphasis on the characters and the stakes they are dealing in, and leaves the (still intense) worldbuilding more as a highly influential backdrop.

Highly recommended read if you like alternative history, wildly fanciful stories, and strange mysteries.
Like all of Jasper Fforde’s oeuvre.