Disney made many changes to the film which writer Ray Bradbury and director Jack Clayton did not intend. Many extra special effects scenes were shot by a second unit director after original production wrapped, and other changes were made before its release. According to the laserdisc commentary by Bradbury, much of his original intentions for the movie were destroyed.
A special-effects sequence that took place at the beginning of the film was cut shortly before the movie hit theaters. In this sequence, the carnival materializes from the smoke of the train, the smoke from the engine "becomes ropes and canvas tents. Tree limbs grow together to form a ferris wheel and a spider web mutates into a wheel of fortune." This sequence was the first time that computer animation was used to animate organic material, and it was combined with traditional animation. The scene was deemed not convincing enough, by Disney executives, and was cut from the film at the very last minute. The deleted scene was described in the issue of "Twilight Zone Magazine" released the same month as the film, which assumed the scene was going to be in the final print.
Ray Bradbury first wrote 'Something Wicked This Way Comes' as a screenplay in 1952, after watching Gene Kelly in Singin' in the Rain (1952), which Bradbury thought the greatest musical ever made. Bradbury showed Kelly the screenplay, and Kelly was so impressed that he wanted to make it his next picture. When Kelly shopped the story around to potential backers, however, he was unable to raise any money for the project. It was only after this failure that Bradbury rewrote the story as a novel, which was published in 1962. Bradbury dedicated the novel to Kelly.
In the spider sequence, the boys are noticeably older, since the scene was re-shot after the rest of the production had been completed. This was used to replace a sequence with a large mechanical hand which, like the animated appearance of the carnival, was deemed too hokey and was subsequently cut from the film.
The music for the film was originally composed by Georges Delerue, but it was rejected by Disney executives, in favor of a less somber score by James Horner. Portions of Delerue's score can still be heard in the film's theatrical trailer.
After a poorly received test screening, Disney held back the release of the movie for a year to re-edit , film additional and replacement scenes (including special effects sequences) with a second unit director, add opening narration, and hire James Horner to rewrite a completely new score, all of which added millions to the budget. When watching the film, it's quite obvious which scenes, such as the spider attack and the mirror maze climax, were filmed nearly a year after original production had wrapped. Reportedly, Bradbury and the original film makers were not pleased with the studio's intervention, nor the effects added. The picture ended up being a flop when it was finally released in 1983, despite Disney's attempts to make it more audience friendly.
In distributor Anchor Bay's DVD, the end of the theatrical trailer (which shows the film's title) has been cropped. The majority of trailer is 1.85:1 aspect ratio, but the last shot is approximately 2.35:1 aspect ratio, which caused confusion among fans. This aspect ratio change in the trailer was created by Disney so as to mask off the Disney and Buena Vista (original distributor, owned by Disney) names. Disney also did not allow its name to be seen anywhere on the DVD package.
The lines: "And in despair I bowed my head; 'There is no peace on earth,' I said; 'For hate is strong, and mocks the song Of peace on earth, good-will to men!' Then pealed the bells more loud and deep: 'God is not dead, nor doth He sleep; The Wrong shall fail, The Right prevail, With peace on earth, good-will to men'" is from "I Heard The Bells On Christmas Day," a Christmas carol based on the 1863 poem "Christmas Bells" by American poet (from Maine) Henry Wadsworth Longfellow.