Substitution Cipher Puzzle

The chilling phrase "Here's Johnny" became an unforgettable moment in cinematic history, famously uttered by Jack Nicholson's character, Jack Torrance, in Stanley Kubrick's 1980 psychological horror film, The Shining. This iconic line, improvised by Nicholson as he axes through a bathroom door, transformed a familiar television catchphrase into a terrifying declaration of madness. Its origin lies in