Egan does a good job of fleshing out this abstract word of two dimensions of space and two of time. I found most of interest in the symbiotic relationship between east-west and south-north seeing creatures, and was less able to fully grasp or enjoy the geometry and physics that took center stage for the middle third of the book. Just as I was growing weary, the third act arrived to save the book for me.

A challenging read, but rewarding enough if you can put in some effort to understand the physics of Dichronauts. I highly recommend the supplemental materials on Egan's website before you begin.