- Campion's entire part in the attempted breakout from Black Dudley, all done after having been tortured.
- Campion making a fool of the big bad at the breakfast table (involving an egg) in that same book.
- Mr. Campion's salvage of the rescue of Biddy Paget, after his more hot-blooded friends deviate from the plan and go on a doomed Roaring Rampage of Rescue.
- Canon Avril, Cool Old Guy and Badass Pacifist, purposely Alone with the Psycho serial killer in order to try to talk him down. While not immediately effective, Avril's words are what lead to the killer's defeat.
- In that same book, Amanda stalking said serial killer in order to get a good description of him to the police, and hopefully save her friend who the killer is after.
- Amanda figuring out who the murderer is in "More Work for the Undertaker" while only hearing about the case from the papers and brief letters from Campion.
- This description of Mr. Campion in the final story Margery wrote:
In his own apologetic way Mr. Campion was a celebrated figure. In his time he had performed a number of services for a great many causes. He was a negotiator and an unraveler of knots, and there were still people who suspected, because of his wartime activities, that he had a cloak and a dagger somewhere concealed. Those who disliked him complained that he seemed negligible until it was just too late.