Asimov's final piece on thiotimoline was a short story titled "Thiotimoline to the Stars", which he wrote for Harry Harrison's "" (1973). In it, Admiral Vernon, Commandant of the Astronautic Academy, gives a speech to the graduating "Class of '22". Vernon's speech explains that thiotimoline was first mentioned in 1948 by a semi-mythical scientist named Azimuth or Asymptote, but that serious study of the compound didn't begin until the 21st century scientist Almirante worked out the theory of hypersteric hindrance. Later scientists worked out ways to form endochronic molecules into polymers, allowing large structures such as spaceships to be built out of endochronic materials. One effect of endochronicity is that if one fails to add water to an object that has reacted to water, the object will travel into the future in search of water to interact with.