I had two main high-level thoughts whilst reading Gnomon, and they’ve made me undecided about whether or not I like the book.
The first was: this is a science fiction version of Foucault’s Pendulum. Gnomon has a deep debt to Umberto Eco and his everything-is-a-great-grand-scheme book from 1988. The whole book is a convoluted conspiracy that maybe didn’t start out being a conspiracy but there were patterns that turned it into a conspiracy it was meant to be all along. In this day and age, when so many people want things to be conspiracy theories that aren’t, and that turns out to be really, really damaging to society, I actually had very little patience for this (and it was the reason that I ended up skipping ahead to the ending after reading about half the book).
The second thought is that you can tell, as he’s laying the groundwork for the conspiracy in the early chapters, that he is his father’s son. John LeCarré is, of course, a master at telling these kinds of stories and Harkaway has learned the mechanics from him. It’s well done and to be admired.
So: while the mechanics are very well done, the overall story wasn’t one I wanted to read. So I didn’t.