In the main Ghostbusters film timeline, Peter Venkman, Egon Spengler, Ray Stantz, and Winston Zeddemore crossed the streams to close Gozer's portal and destroy the Stay-Puft Marshmallow Man. This one-shot asks what would have happened if they had not.
Thirty-one days after that fateful failure on the Temple of Gozer rooftop, New York City has descended into chaos and ruin, now ruled by the Stay-Puft Marshmallow Man. The Ghostbusters are alive but imprisoned, their city overrun by an army of miniature Stay-Puft creatures called Mini Pufts. Janine Melnitz appears in a cameo role. Dana Barrett and Louis Tully, still possessed by Zuul and Vinz Clortho in their Terror Dog forms, have minor roles with an in-story twist. A new entity, Tempore Ruga, is introduced as part of the divergent mythology.
The story eventually centers on the Ghostbusters finding a way to reset the timeline by engineering the moment they should have crossed the streams in the first place. The irony at the heart of the story is that Gozer itself ultimately suggests crossing the streams as a solution. The timeline resets at Peter's "Let's show this prehistoric bitch how we do things downtown" line, with Gozer performing its aerial flip back onto the altar as events unspool to their proper conclusion.
Equipment appearing in the issue includes the Proton Pack, Particle Thrower, PKE Meter, Ecto-1, Ghost Trap, and the Aura Video-Analyzer. Key locations are the Firehouse, 550 Central Park West, and the Temple of Gozer.
IDW teased the Deviations event on December 10, 2015. The concept behind the line was for IDW to pick notable divergence points in its bigger licensed properties and publish one-shot what-if stories exploring those alternate paths. For the Ghostbusters title, the chosen scenario was: what if the team never crossed the streams on the Temple of Gozer?
On December 11, 2015, Kelly Thompson was announced as writer and Nelson Daniel as artist. Two covers were previewed: Daniel's regular cover and Dan Schoening's subscription variant. The story was confirmed to pick up approximately one month after the non-crossing, with Gozer ruling New York City in the guise of the Stay-Puft Marshmallow Man. The creative team indicated that Dana Barrett and Louis Tully would appear with "a bit of a twist," and that new minions would be introduced.
On January 5, 2016, an unlettered panel was included in IDW's 2016 release preview, depicting Peter and Egon leaning on the hood of Ecto-1 being addressed by a miniature Stay-Puft.
On March 14, 2016, ahead of the March 16 release, IDW posted an interview with Thompson and Daniel alongside a cover image and a five-page preview. Thompson noted that the concept arose from a conversation with editor Tom Waltz about another project, and that the non-crossing scenario was one of Waltz's illustrative examples during that discussion. Daniel, citing affection for both the original films and The Real Ghostbusters animated series, combined visual influences from both for his character designs, including giving Egon blonde hair in the RGB style.
