Quarantine is an earlyish Greg Egan book. I think. I found a terrible-condition copy at a used bookstore and I felt pretty sure I’d never seen another edition of it anywhere before, so yeah. It’s sort of a detective story/technothriller kind of thing based on quantum mechanics and the idea that every time people make choices and collapse waveforms we’re killing off whole universes. Also, at some point in the 2030s all the stars disappeared; the solar system was isolated in its own little bubble.
There was a lot of exposition and some good twists (by the end it doesn’t really feel like the book you started). Egan returned to similar themes in one of the stories in Crystal Nights, “Singleton” though I don’t think the stars being gone was a part of that. In fact that story felt like a mirror reflection of this novel.
Greg Egan is amazing. I love his novels but his short stories seem almost more awesome because they get to crystallize some idea and let you spin it yourself. Crystal Nights and Other Stories is an excellent collection of science fiction. There are stories about interstellar travellers who explore a rogue planet through digitally transmitted personalities into grains of rice and insects. There are stories about having an artificial intelligence child when you are worried about what the Many Worlds Interpretation of quantum physics implies about all those yous for whom life hasn’t worked out so great. There’s a story about an alternate version of Alan Turing and C.S. Lewis and how faith you cling to desperately utterly fucks one of them up. Such a good book. It’s the kind of thing that might make you want to read science fiction if you didn’t already. Or maybe I’m projecting too much into that. I’m going to recommend it far too much for a while.