Doughnut is the story of Theo Bernstein, a physicist who finds himself divorced, poor, and out of a job after blowing up the Very Very Large Hadron Collider. Theo is so far out on the cutting edge of physics that most of this book reads like science fiction. After spending a year working at a meat packing plant, an old mentor, Pieter, gets Theo a job at a hotel that's clearly not a hotel and wills him probably the weirdest bequest on record: an old bottle, an apple, a pink compact, and a letter that introduces him to YouSpace.
YouSpace is not just a pocket universe, it's a pocket all-the-universes. If Theo can access it, he can go to any multiverse he chooses. Holt takes the multiverse theory to the point of absurdity:
"Multiverse theory states that in an infinite multiverse there's a universe for every possibility. Thus, if I formulate the possibility of a universe where Max is hiding out in YouSpace, it'll exist and I can go there. Question is, would it have existed if I hadn't conceived of it, or am I calling it into existence just by thinking about it?" [Theo explained.]Since his mentor convinced some of the richest people on the planet (in our reality) to invest billions in YouSpace, his partners force Theo to take up Pieter's work. At the derelict hotel they own, Theo works on the equations for hours, days, before determining that of course YouSpace is impossible--in this reality. If this wasn't weird enough, Doughnut gets even weirder. If I tried to use a flowchart to explain the plot, it would probably end up looking like a Klein bottle and then my laptop would explode.
"Oh, for crying out loud." (196)*
Theo does managed to get into YouSpace and then goes on a quest to track down Pieter. When it turns out his brother, Max is involved, Theo goes after him as well. As he pursues them, the story gets even increasingly surreal and hilarious. As Holt puts it, things get as "troublesome as a Klingon battle cruiser at a garden party" (96)*. This would be an interesting enough story as is, but Holt goes even farther and turns Doughnut into a remarkable tale of science fiction. I highly recommend it!
* Kindle version.