- "This was all for you, Caul. When Palpatine marched your brothers to their deaths, I vowed that the Empire would never have you."
- ―Headmaster Gentis to his son, Caul
Caul was a friend of Laurita Tohm and often encouraged Tohm to live life less stringently. Caul, however, was secretly a member of Headmaster Gentis's rebel coup and locked Tohm in an Imperial starfighter prototype along with fellow co-conspirator Shens, so he would not get in the way of their attack on the Imperial Palace. Afterwards, he was present with Gentis during the latter's attempt at recruiting an Imperial General into participating in the coup, where Caul put a blaster to the general's back.
Caul later participated in the fight amongst the cadets against Vader and his new forces. However, he ended up shot by Tohm, the latter of whom cruelly called his name to get his guard to drop (as he had believed Tohm was on his side from being called). Gentis, his father, then mourned for his death, and also vowed to protect Caul's son. Unfortunately, he was unable to do so as Palpatine promptly executed Gentis for his coup, rendering both father and son charred husks.
- Star Wars: Darth Vader and the Ghost Prison 1 (First appearance)
- Star Wars: Darth Vader and the Ghost Prison 2 (Indirect mention only)
- Star Wars: Darth Vader and the Ghost Prison 3
- Star Wars: Darth Vader and the Ghost Prison 4
- Star Wars: Darth Vader and the Ghost Prison 5 (First identified as Gentis)