This is what would be called a “literary science fiction” novel in that it’s clearly SF yet is written by a writer with a “literary” background rather than one in the SF genre, and so whose approach would be expected to vary from the interests of genre science fiction writers and readers. Mandel (the St. John is a middle name) came to prominence a few years ago with STATION ELEVEN (2014), which I haven’t read but which I gather was about the aftermath of a worldwide plague (it won an Arthur C. Clarke Award); after that came THE GLASS HOTEL (2020), which seemed to have such a slight genre element that haven’t even bought a copy. (Too many books…)
SEA OF TRANQUILITY is about time travel and the idea that the universe might be a simulation, focusing on a situation the author calls an “anomaly” and which is likened to a “file corruption” (as if the simulation is run on some huge computer). The “anomaly” manifests via various people in different times and places (including the Moon) who experience a momentary connection. That’s the boiled down technical summary.
