The Heterodyne Boys and the Pneumatic Oyster

The Heterodyne Boys and the Pneumatic Oyster is one of the published adventures of Bill and Barry Heterodyne which either didn't happen, did happen and has been highly distorted, or actually did mostly happen.

Agatha picked it up in Gil's library and read " before realizing why Gil might be as reluctant to share the stories showing his father in a poor light as Agatha is with the stories mocking Punch and Judy.

(The tar pit falls under "highly distorted" at the very least.)