The Temporal Duplication Theory is the 32nd Proposed Serial in Spectral Shadows. It is preceded by Serial 31 - Machine Messiah and succeeded by Serial 33 - The Second Sitting for the Last Supper. It is currently not being worked on, meaning that the only available material is the summary on the Synopsis Page.
The summary is as follows:
A miscalculation sets Jon down in his own past, causing him to lose all memories after that point in time, and he witnesses himself committing the most shameful acts of his life.
Meanwhile, Jon's traveling companions enlist the aid of the escaped research animals to help get Jon back into the ship so they can get him away from Chikyu and restore his memory. But no one is sure which Jon is the one from the future.
The adventure also brings romantic problems for Sonny when she encounters Hazel, who was her former love interest in her life as a dog. But she has by this time been romantically involved with Jon for quite a while, and her sense of loyalty to both loves interests seems equally strong.