This is a bit of a whistlestop tour of, well, the world’s undeciphered scripts. It starts off by exploring some scripts which have been deciphered — Mayan, Egyptian hieroglyphs, Linear B — and discussing how those decipherments were accomplished, and what if anything might be relevant in the study of other languages. After that, it introduces a few different undeciphered languages, including Linear A, Rongorongo and the Phaistos disc, discussing what we know and what we don’t, giving a little of the context, and figuring out to what extent any claimed modern decipherments are real.
It’s an interesting read, and reproduces a lot of photographs, sketches and diagrams showing these scripts and ways of deciphering them. Those images are probably really useful if you think in a very visual way, but they were somewhat limited for someone like me with no visual memory or imagination! It got a bit technical at times, but if that’s your interest then I’ve no doubt it’s useful and quite probably inspiring (in the sense of making you want to dig into these mysteries yourself).
I think Robinson’s attitude toward claimed decipherments is fairly cautious and conservative, but he takes the time to explain what his reservations are and what the field as a whole thinks of the ideas. It’s not always a riveting read, but it was overall pretty interesting and easy to absorb information from. Probably even better if you are, like I said, a visual sort of thinker/learner.