Second paragraph of third chapter:

No one had ever tried to orbit a toroidal body. Themis was 1300 kilometers across and only 250 kilometers wide. The torus was flat along the outside, and 175 kilometers from top to bottom. The density of the torus varied radically, supporting the view that it was composed of a thick floor along the outside, an atmosphere about that, and a thin canopy arching overhead holding the air inside.

When I started my research on science fiction books set in 2025, this was one of the first that emerged. The date in the first two chapters is specified as May 2025, but we are told that the end of the book is set eight months or so later, so I guess it eases into 2026. I am still counting it for 2025.

This is John Varley’s best known book, as measured by Goodreads and LibraryThing readership. Published in 1979, it’s a clear riposte to Ringworld (1970) and Rendezvous with Rama (1973), in that the protagonists discover a vast alien structure, but it’s permanently in our solar system (orbiting Saturn as a more obscure moon) and also sentient, a huge wheel with individual segments of the rim each having their own micro-environment. Our protagonists, a group of sexy astronauts, go through the usual quest to find out what is really going on and make discoveries about themselves as well as about the world. I must say that I enjoyed it a lot. You can get it here.

As with the last two sf stories set in 2025 that I sampled, there is an interesting look at reproductive rights. When the crew first land, the women all discover that they have been made pregnant by the entity behind it all, and the medical chap on the crew terminates the pregnancies without a fuss. There aren’t a lot of sf books that deal with abortion.

Next in my list of books set in 2025 is The Running Man, by Stephen King.