A headmaster and his wife come back to their home to discover that a section of a window pane in one of their doors has been precisely cut out. As they search the house for anything that might be missing, they encounter a young man sitting in one of their rooms, and the phone is out of order. The young man’s demeanor is odd yet courteous. He claims to have come from Australia and was acquainted there with an old friend of the headmaster. He possesses extensive personal information about the family, lending credibility to his story. Nonetheless, he undeniably has a sinister side, engaging in extreme “practical jokes,” brandishing a gun, and participating in an especially violent boxing match.