The fourth season of The Twilight Zone aired Thursdays at 9:00–10:00 pm on CBS from January 3 to May 23, 1963. This season broke with the previous seasons in presenting hour-long episodes instead of the earlier half-hour episodes. A very different and more complex set of graphics was used for the intro, and Rod Serling's narration changed from the earlier seasons as well: "You unlock this door with the key of imagination. Beyond it is another dimension. A dimension of sound. A dimension of sight. A dimension of mind. You're moving into a land of both shadow and substance, of things and ideas. You've just crossed over into the Twilight Zone."