Plus X was written by an Englishman, Bad Medicine by an American. Both stories were first published in 1956, in the classic pulp science fiction magazines Astounding Science Fiction and Galaxy respectively.
Plus X is about a human prisoner of war on an alien planet; Bad Medicine is about a homicidal maniac in New York. Both men use psychological methods to escape their condition.
I don’t want to be a spoiler, so will say only a little more about the stories.
Plus X by Eric Frank Russell
John Leeming is the hero of this story. He is a prisoner of war, captured by a reptilian race. He escapes by fooling the enemy, persuading the reptilians that earthmen and their alien allies have invisible, and dangerous, companions.
For me, one of the best scenes is when one of the enemy aliens interrogates another earthman prisoner - who knows nothing about Leeming’s lies - about these companions to get some independent confirmation. This man has no idea what his captor is talking about, but manages to give very good answers that confirm the story.
He says, “Where did you get this information?”, and when asked whether the invisible companions might manage to take over some of the reptilians, says with great menace, “I wouldn’t be surprised.”
It is all very amusing and very clever.
