Major Curtiss

In the short story The Mystery of the Baghdad Chest, Major Curtiss is a friend of Edward and Marguerita Clayton. He is among the guests of a party hosted by a mutual friend Major Jack Rich. Just before the party, at seven thirty in the evening, Curtiss had had a drink with Edward Clayton at the club. Edward had told him that, although invited, he could not attend the party because he had to go off to Scotland on a business trip. He intended to stop by Rich's house to convey his apologies on the way to the railway station.

When the body of Edward was found murdered in a Baghdad chest in Rich's home, Poirot was asked to help clear Major Rich. Curtiss was among the first people to be interviewed by Poirot. Curtis is described as a man of about forty and of soldierly build, with dark hair and a bronzed face.

In the expanded story, The Mystery of the Spanish Chest, the character is renamed "Commander Jock McLaren". He plays much the same role but his backstory is considerably expanded. In the shorter story, Poirot merely surmises that Curtiss has a dark passionate temperament and is secretly in love with Marguerita Clayton. In Spanish Chest, his love for her is common knowledge. He knows Marguerita from childhood and has always been in love with her even after her marriage. Marguerita knows all about his feelings. She tells Poirot it has become somewhat of a habit and he had basically devoted himself to her service.

Portrayals
In ITV's 1991 adaptation of Spanish Chest, the character's name reverts to that used in the shorter story. Here he becomes "Colonel Curtiss" and his backstory is much as in the expanded story. He has a even greater role in the adaptation. He can become violent when Marguerite's honour is threatened (he had fought a duel for her in the past). Poirot uses this tendency as part of the solution of the crime. Colonel Curtiss is portrayed by John McEnery.