It seems that readers are not prepared to leave me in peace over the Giants series. No sooner had the fourth book, Entoverse, been released, than the requests and suggestions started coming in for a further one. Eleanor Wood and Jim Baen added their contribution to the arm-twisting over dinner one night in New York. I had problems seeing how a suitable story could come together, however, and it was some considerable time later before I was able to come up with an outline to eventually set things moving.
Two themes were especially popular among the readers' requests: (1) "Koriel's story"--an account of the group of Lunarians left stranded on the relocated Moon, who made it to Earth and became the founders of the human race. And (2) something set on Minerva before its destruction, showing more of the civilization that Charlie and Koriel were from. The reason I had reservations was that to me, a "series" implies following the characters that readers have gotten to know, which in the case of the Giants means Vic Hunt, Chris Danchekker, the various Ganymeans that they meet in the earlier books, and so on. But Minerva and its history all existed fifty thousand years before any of those characters existed. I couldn't see a way of getting them together without having to pull some unacceptable rabbit out of a hat, such as a suddenly introduced technology that the previous stories hadn't laid some kind of groundwork for in any way.
When I mentioned this in a posting on the Bulletin Board, a reader wrote to remind me of something that I had completely forgotten: In the closing chapters of Giants' Star, the physics of some kind of time transfer is already anticipated after all. The tussle of the two supercomputers VISAR and JEVEX over control of the black-hole transfer torroids opened up some kind of time gate that the fleeing villains were drawn into, and hurled back to the vicinity and time of early Minerva. Curious physicists like Hunt and the Thuriens were hardly going to let something like that pass by without further investigation. So after the emergency on Jevlen was taken care of, as described in Entoverse, it seemed that this would be the next area for the characters to turn their attention to. I had also received enthusiastic reader mail about the physics of alternate universes described in Giants' Star and The Proteus Operation. This was drawn to a large degree from the Many Worlds interpretation of quantum mechanics presented by the Oxford University theoretical physicist David Deutsch, in the picture he terms the "Multiverse." And this gave me a title too.