Pilar Seurat later played Sybo on Star Trek another Gene Roddenberry creation.
A young Ed Asner portrays Charles Perry.
Captain Rambridge tells Lieutenant Rice, "I am delighted to see you hoisted on your own petard." This phrase is from Shakespeare. Hamlet utters these words in Act 3 Scene 4, while he is talking with his mother. Hamlet insinuates that he is going to outwit his two 'schoolfellows', Rosencrantz and Guildenstern, who have been ordered to take him to England and have him killed.