The prisoners become suspicious of each other when their captors claim they have received cooperation in obtaining military secrets, which is further complicated by each one's past and ethnic origins, along with the unexpected appearance of high-ranking Earth officers among the hostile aliens.

The Earthmen are subjected to various interactive images of relatives and friends which have been implanted in their minds during questioning, allowing them to feel a false sense of security, or surfacing deeply hidden emotional conflicts.

Unexpected accidents and deaths having occurred during the test, the Ebonites –who are, in actuality, a peaceful and honorable alien civilization– ultimately demand that such an immoral and inhuman experiment should end at once.

Nevertheless they fail to prevent one last man from being killed, one of the conspiring Earth officers thought to be an illusion created by the Ebonites to trick the captives into revealing more information.

Perhaps they will learn something.Originally scheduled to air on November 25, 1963, this episode was delayed until December 2 due to television coverage of the state funeral of President John F. Kennedy.