His parents were unable to handle him, so they gave him to a welfare agency. When he grew up, he joined the Chapter of Saint Anthony and killed them, blaming them for his abandonment.
At first he idolised Magna Yong. Then as he felt his work was underappreciated, the idolising turned to resentment until he finally decided to become Magna himself. When the Chapter came to Betrushia and found out about the Keth, Yong wanted to allow its escape, believing it to be the will of St Anthony. De Hooch disagreed, using the opportunity to overthrow the Magna and gain control of the Chapter, as well as help the Seventh Doctor destroy the Keth. However, he was killed by Yong shortly afterwards. (PROSE: St Anthony's Fire)