Star Trek: Deep Space Nine: Season 5, Episode 16

5 - 16: Doctor Bashir, I Presume

Dr. Lewis Zimmerman arrives on DS9 intending to use Dr. Julian Bashir as the model for his new Long-term Medical Hologram, but when Zimmerman's plans threaten to unveil a dark secret that Bashir has carried since childhood, Julian is forced to make a life-altering confession.