The cavernous mouth of hell was an iconographic convention representing the threshold of eternal damnation in medieval England and Europe. The gaping mouth of a fierce beast captured the essence of everlasting isolation from God, making it a dramatic way to represent hell’s perpetual threat for devout Christians. Created in tenth-century Anglo-Saxon England, the mouth of hell spread throughout continental Europe, and detailed Lucifer’s Fall, the Harrowing of Hell, or the Last Judgment. This horrible visage was represented in sculpted tympana, paintings, mosaics, and stained glass, and by the fourteenth century, the mouth of hell appeared in lay religious vernacular theater as a constructed stage scene and prop. Theatrical effects contribute...