Shadow Show

Story, first published: The Magazine of Fantasy and Science Fiction, Nov. 1953

A group of nine biologists has been isolated on an asteroid, attempting to create beings who can survive on other planets. Earthlings must be "strong" when they encounter other intelligences. The group is oppressed by guilt over their activities, compounding the psychological problems of isolation. To amuse themselves and remain sane, they put on a Play in which each member of the group imagines a character in a continuing drama displayed on a screen, like a television soap opera.
When the story opens, one of the team in opposition to the project has just died, but the identity of the character he created is unknown to the rest of the group. When they again begin to play the drama, however, all the nine characters are present, which gives rise to all kinds of speculations: who is Character Number Nine? Is it a bad joke? Is the machine itself sentient? Or is Henry a ghost? Finally, Henry's character is unmasked as the Philosopher, the most assertive character in the play, and the mystery is solved.

Ewald, Robert J.: When the Fires Burn High and the Wind is from the North, p.71