Colonel Carbury is described as an "untidy stocky man of medium height with a semibald head and vague, mild, blue eyes". He has a "somewhat ragged brindled moustache". He does not look like a soldier, does not look very alert, and is not "in the least one's idea of a discplinarian". However, in Transjordania, he is "a power".
Colonel Carbury is an old friend of Colonel Race. Colonel Race writes a letter of introduction for Poirot when he goes to stay with Colonel Carbury in Amman.
Colonel Carbury mentions the case of Mrs Boynton's death to Poirot, saying that there is nothing odd about her death, but he has an idea that her family killed her. He says that there is nothing to go upon, and the easiest thing to do would be to let it go, but he is a tidy man, and wants to clean a mess up when he sees one.
Colonel Carbury's appearance is untidy, as his tie is under his left ear, his socks are wrinkled, and his coat is stained and torn. However, Poirot perceives the inner neatness of Colonel Carbury's mind, with neatly sorted facts and impressions, which is why he describes himself as a tidy man. Colonel Carury desires to know exactly what occured and how it happened.
Colonel Carbury gives Poirot facts about the case, and asks for his professional opinion. He also asks Dr Théodore Gérard to tell Poirot the facts he had noticed about the case.
Poirot says that he will undertake to find out the truth of how Mrs Boynton died, but that they may not have any proof that would be accepted in a court of law. Colonel Carbury asks Poirot to satisfy him of what realy happened, and he will then judge whether action is possible or not.
Colonel Carbury later expresses the opinion that Raymond Boynton is innocent, as he is the most likely person, and in detectie stories, the most likely person is usually innocent.
Colonel Carbury likes detective stories, and says that he has read thousands of them. He asks Poirot to write a list of significant facts, including things that do not seem to mean anything but are very important, as detectives do in stories. When Poirot writes this list, Colonel Carbury reads it with great satisfaction, saying that Poirot has made it difficult, and seemingly irrelevant, which is "absolutely the authentic touch".
During the denouement, Poirot has Colonel Carbury sit behind a table in an official position. Poirot adjusts Colonel Carbury's tie, but he unconsciously tweaks his tie around under his left ear again.
Appointment with Death (1988 film)
In the 1988 film adaption of Appointment with Death, Colonel Carbury is portrayed by John Gielgud. Here he is personally acquainted with Poirot. Poirot does not need a letter of introduction from Colonel Race. Carbury tells Dr Sarah King that he and Poirot were together in India or Burma. Although his appointment is not specifically given, Poirot introduces him to Dr King as someone who keeps the peace in the Holy Land, suggesting that he is a member of the Palestine Police. Certainly he undertakes duties consistent with being a policeman--he is informed when Jefferson Cope and Miss Quinton had gone missing in Qumran. He also undertakes the investigation into the death of Mrs Boynton. However his cap badge is not that of the Palestine Police force.
Appointment with Death (2008)
In the 2008 ITV adaption of Appointment with Death, Colonel Carbury is portrayed by Paul Freeman. Here he is also personally acquainted with Poirot although he is not handling policing duties. He is in fact working for the Foreign Office (often a euphemism for the Intelligence Service) and in Syria on the trail of a gang of slavers. Syria where the events of the plot take place is under French jurisdiction at that time and the troops who work for Carbury are French, suggesting that his was some kind of joint operation.