The Surprise on the 13th Floor

"The Surprise on the 13th Floor" was a Goosebumps story and contest by R.L. Stine made exclusively for the magazine Disney Adventures. The November, 1996 issue advertised a contest to "Finish R.L. Stine's story." Stine provided the opening of the story and the conclusion would be chosen out of the entries sent to the magazine, with the winning conclusion being featured in the magazine's March, 1997 issue. Contestants were tasked with writing a 1200 word middle and end for the story. The winner of the contest was Cheryl Hotchkiss.

Plot
Jack and his friend Lindsay head to Jack's uncle's magic shop, that resides on the twelfth floor of a building. The kids board an elevator, only to stop at the thirteenth floor, which is strange as the building only has twelve floors. The elevator doors open and Jack and Lindsay see a boy and girl that look exactly like them. The pair are evil versions of themselves with sinister grins on their faces. They tell the originals that Jack's uncle tried to do a spell that involved the mirror reflections of Jack and Lindsay that would do the opposite of what the kids would do, but the spell failed and created exact doubles of the kids. Jack's uncle then created a magical thirteenth floor to keep them from causing trouble.

The doubles show Jack and Lindsay the power of the thirteenth floor. It can create whatever you wish to be a reality, but you have to share the wish with someone else or only you will see it. Jack visions a basketball court, while Lindsay imagines being on a fashion runway. While Jack and Lindsay are busy with their fantasies, the clones head for the elevator, telling the two that they were bored of their lives in the thirteenth floor and now want to take over their old lives instead. Jack says that life is more fun with adventure and mystery, and that a room where you can have everything you want isn't a life worth living. Jack and Lindsay fight the clones and make it inside the elevator in time. However, as the elevator starts to go down, Jack notices that Lindsay has an evil grin on her face.