What Have I Done?

One of the most literary and innovative science-fiction writers of the early 1950s, Mark Clifton introduced sophisticated psychological insights into the characters who populated his tales of alien encounters, expanding technology, revolution against political theocracy, and space colonization. The title tale, centering on a psychologist who uncovers a hidden colony of otherworldly invaders and craftily orchestrates their doom, is accompanied by nine other perceptive and witty stories.