Star Trek: Mission Gamma, book 03 : Cathedral
Michael A. Martin et Andy Mangels2002

As a small child, Jules Bashir underwent illegal genetic enhancements that forever altered the natural course of his life. As an adult, ever since the day he discovered what his parents had done, Dr. Julian Bashir has wondered what he might have become if "Jules" had been allowed to live, certain he would never know the answer. But when the lure of a strange alien artifact in the Gamma Quadrant inexplicably begins to reverse Bashir's enhancements, the person he had thought long dead is given a second chance at life.

Ninety thousand light-years away, as the crew of Deep Space 9 tries to comprehend a shocking tragedy, Ro Laren makes a fateful decision about her life aboard the station. And although political maneuvering and failing diplomacy have already extinguished all hope of a real, lasting peace between Bajor and Cardassia, one man's search for his true calling may lay a new foundation for the future.