Ellery Queen editor Frederic Dannay contacted Asimov in the fall of 1975 with a story proposal: the August 1976 issue, which would be on the stands during the United States Bicentennial, would include a contemporary mystery set in 1976 and a historical mystery set in 1876. He wanted a science fiction mystery set in 2076, and Asimov agreed to write one. Asimov's original title for the story was "Death at the Tercentenary", but when the story appeared he decided he liked Dannay's title better.
This story begins on 4 July 2076. The United States itself is no longer a sovereign country, but part of a Global Federation. The story details the speech of the 75th president, Hugo Allen Winkler, who is described by Secret Service agent Lawrence Edwards as a "vote-grabber, a promiser" who has failed to get anything done during his first term in office. The president is walking near the Washington Monument, and suddenly disappears. He reappears very shortly afterwards on a guarded stage and gives a stirring speech which is quite different from the kind he usually makes. Two years after that occurrence, Edwards talks to a government official named Janek, to whom he describes a possible murder weapon, a disintegrator. Edwards explains that a robot double of the president exists as a security measure, and then correctly surmises that it was not the robot double who had died, but the president himself. The robot had then taken office.