Short story about alien suffering memory problems trapped in a house

Question

Looking for title or author of a short story where a man inside a house that has no windows or doors tries to remember things as if he is suffering from some kind of amnesia. The reader follows what the man is thinking and I think that there are some people in the house at some point but they keep disappearing; I don't' remember if he actually interacts with the people. At one point the man stares at a model of a spacecraft or a plane sitting on the top of a piano and he tries to remember how he is supposed to relate to the model. He doesn't remember the model being there the last time he looked at the piano; who put it there? What is the piano for? He then gets this funny feeling about how things are all ready for him, all the time. Food, clothing, I think there is a speakerphone somewhere that gives him instructions.

By the end he sees someone leaving the house through a latch and follows the person outside the house. The house is a kind of a cottage in a woody area and the police appear and surround him. That's when we learn that he is an alien metamorphosed into human that had been captured during the hibernation status and put in the house to be studied. Who is the author, the title ? Please help me.

Answer 1

This is a 1955 short story by Brian Aldiss called "Outside". It was first published in New Worlds #31, January 1955, which is available at the Internet Archive.

Relevant quotes:

At one point the man stares at a model of a spacecraft or a plane sitting on the top of a piano and he tries to remember how he is supposed to relate to the model

Almost furtively, he glanced round as the darkness slipped away, and then he looked at the big piano. Some strange things had arrived on the shelf from time to time and had been distributed over the house: one of them stood on the top of the piano now.

It was a model, heavy and about two feet high, squat, almost round, with a sharp nose and four buttressed vanes. Harley knew what it was. It was a ground-to-space ship, a model of the burly ferries that lumbered up to the spaceship proper.

That had caused them more unsettlement than when the piano itself had appeared in the store. Keeping his eyes on the model, Harley seated himself at the piano stool and sat tensely, trying to draw something from the rear of his mind ... something connected with spaceships.

By the end he sees someone leaving the house through a latch and follows the person outside the house.

Jagger was leaving his bedroom, taking no precaution to be silent .... Unhesitatingly, Harley followed.

There are no trees, but there are mountains.

... the police appear and surround him.

Buildings loomed about him. He simply ran for the nearest light and burst into the nearest door .... A thin man sat alertly at the desk; he had a thin mouth. Four other men stood in the room, all were armed, none seemed surprised to see him.

That's when we learn that he is an alien metamorphosed into human that had been captured during the hibernation status and put in the house to be studied.

He choked on the words. They were no longer pronounceable. He felt his outer form flowing away like sand as from the other side of the desk revolver barrels were levelled at him.