He had booby-trapped the oxygen cylinder from force of recent habit, then realized his mistake and also booby-trapped the hydrogen cylinder. Davenport is convinced, and orders Farley's arrest. The author originally intended for "The Dust of Death" to be a fourth Wendell Urth story, but since it was due to appear in the premier issue of "Venture" and the Wendell Urth stories had all appeared in "The Magazine of Fantasy and Science Fiction", he decided to remove Urth. The story does feature agent H. Seton Davenport, who appeared in the first two Urth stories. When Asimov prepared the story for inclusion in "Asimov's Mysteries", he considered restoring Urth, but, as he put it, "inertia rose triumphant over all". In line with accepted astronomical knowledge when the story was written, Asimov describes Titan as having an atmosphere composed of hydrogen and methane. Subsequent observations by the Voyager and Cassini spacecraft have since established that the majority of Titan's atmosphere is actually nitrogen.