What is demon with a glass hand?

"Demon with a Glass Hand" is a science fiction short story written by Harlan Ellison, first published in 1964. The story follows Trent, a man who wakes up in a strange building with no memory of who he is. He discovers that his left hand is made of glass and contains a computer that holds information about the future.

As Trent navigates the building and tries to piece together his identity, he is pursued by alien creatures known as Kyben who want to destroy him. Trent learns that he is from the future and that he has been sent back in time to prevent a catastrophe that could destroy humanity.

The story explores themes of identity, fate, and the impact of technology on society. It has been praised for its imaginative storytelling and unique premise. "Demon with a Glass Hand" won the Writers Guild of America Award for Outstanding Script for Television in 1965.