Paul Durham has begun experimenting on his own mind. He uploaded a copy of his neural patterns - everything that makes him who he is - into a computer simulation. The more he experiments, the more the lines between the real person and the virtual person begin to blur. What he discovers there, out at the edge of consciousness and the pattern that defines him, give him an impossible idea. A permutation city, where immortality might be possible.Join the Hugonauts book club on discord!Or you can watch the episode on YouTube if you prefer videoSimilar books we recommend: The Hidden Girl and other Stories - Ken Liu (our interview with Ken Liu: https://hugonauts.simplecast.com/episodes/ken-liu)The Last Question - short story by Asimov (available free here: https://users.ece.cmu.edu/~gamvrosi/thelastq.html)Diaspora - Greg Egan