Based on the short story "Brenda" by Margaret St. Clair. The story was first published in Weird Tales (March 1954).
Douglas Hayes wrote the teleplay under the pseudonym "Matthew Howard."
Host: There's something rather remarkable in the scope of imagination peculiar to children. they project and dream and fantasize with beauty and simplicity and faith, in a manner that somehow eludes us as we grow older. This is Brenda, and Brenda has a playmate. It comes to her in part because of loneliness, and what I wish for you is that you never get that lonely.