The value of observation is a central theme of The Absent Author. At the center of every mystery story is a problem that cannot be solved without paying close attention to all the facts at hand. Every fact in a mystery story is a potential clue for both the characters and the reader, and as more facts are gathered, the investigators must re-examine their evidence in light of new information. They must form working theories and listen and look carefully to notice the hidden connections between events. The characters in The Absent Author repeatedly demonstrate good investigative techniques through mapping, interviewing, and evaluating their assumptions.

The Wallis Wallace books that Dink enjoys are filled with clues and investigations, positioning Dink to assume the role of a detective when Wallis Wallace goes missing. The initial clue comes in the form of an offhand comment in Wallace’s letter: “Short of being kidnapped, nothing will stop me from coming!” (9). Dink’s experience with Wallis Wallace’s mystery novels has taught him to take every piece of evidence seriously; had he not been trained to pay attention to details, the investigation might never have started.

Every observation that the children make throughout the story helps them to recreate the sequence of events and contributes to their ability to solve the mystery.