Many readers have asked me if I wrote the two stories separately and then put them together later on, but that’s not how I did it. I wrote them in the same order as they appear in the novel, alternating one with the other. Doing this sparked and fired up my imagination in real time. Perhaps it’s like two construction crews on opposite sides of a mountain, digging to create a single tunnel. Drilling operations like this naturally require specialized surveying equipment, with the two holes meeting up at
