Jack Mortley worked at Snooker and Woe. Attorneys at Law. Jack hired Dennis Wood to work as the buildings janitor. Sadly, although Jack has written all of Dennis's paychecks for years, he still doesn't know the janitor's name. His only appearcence is in Leven Thumps and the Whispered Secret.
Jack is made out to be a particularly unobservent and egotistical person. Despite knowing Dennis for years, Jack still has to ask his name before telling the janitor that there is a spill in the breakroom.
The actual Jack Mortley never appears. He is merely mentioned by Dennis as he is thinking back on his career at Snooker and Woe.