It’s been thirty years since Zero Hour: Crisis in Time changed the way we think about DC Comics. It’s an event with an interesting reputation today among comic fans—a sort of waystation on the twenty-year journey from Crisis on Infinite Earths to Infinite Crisis. A stop for maintenance, self-reflection, and in hindsight, a confirmation on what a “Crisis” event would mean to the DC Universe. It’s also an event that’s notoriously difficult to explain—one which seems to necessitate discussion of complicated topics like the “pocket universe” of the Legion of Super-Heroes, the oft-forgotten Armageddon 2001 and conflicting histories of Hawkman.

We’re going to give it a try anyhow. In honor of its 30th anniversary, we’re here to clear up exactly what Zero Hour was meant to do, how it happened, what went down and what came out the other side.
 

The Power Behind the Hour

Depending who you ask, Crisis on Infinite Earths was a project that had to happen. Fifty years of accrued comic book history, often self-contradicting with a sprawling multiverse of imaginary stories and alternate realities, made the DC Universe long overdue for a streamlined cleanup. Crisis on Infinite Earths was designed as one last epic blowout before the decks were cleared—a way to start fresh and give new comic buyers a fresh jumping on point and a clear way to understand the universe going forward. Many new titles were launched following Crisis on Infinite Earths to this effect, and other ongoing titles took on a new status quo. Perhaps even more important, however, was the release of Crisis masterminds Marv Wolfman and George Pérez’s The History of the DC Universe, a two-volume set narrated from the perspective of Crisis’s Harbinger which spelled out the entire new status quo of the DCU from that point on.

The post-Crisis continuity was mostly a success in its attempts to disentangle DC history…but as stories accrue and different creative teams pull in disparate directions, the massively collaborative nature of the shared DC Universe means that, in time, there are bound to be contradictions. A new launching point for Wonder Woman, for example, now implied that Wonder Girl had been active longer than Wonder Woman. A new Hawkman origin had Hawkman arriving on Earth from Thanagar when he had already been established as a former Justice League member. Even after the immediate collapse of the multiverse in favor of a new, conceptually easier to follow single reality, the continued existence of the Legion of Super-Heroes now necessitated the existence of a “pocket universe” to explain how they could continue to persist when their origin was so closely tied to a version of Superboy who no longer existed.

Zero Hour: Crisis in Time was devised behind the scenes as a way to provide a sort of “soft patch” to continuity, gently realigning the unforeseen snarls in the DCU that had been left over from, raised by, or accrued since the previous Crisis. A major event would necessitate enormous ramifications for the comic book universe as we knew it and could provide any straightening of history or continuity that any particular character or title needed. It’s an idea that has proven crucial to the maintenance of DC’s ecosystem, with each Crisis event since presenting a new opportunity for creative teams to straighten out complications or mistakes with little need for an overly elaborate explanation. If Zero Hour has any true legacy, it’s in its example on how to maintain a long running comic book universe.
 

Creating a Crisis

But what is Zero Hour about? To understand the narrative forces converging in the event, you have to be familiar with two major preceding storylines: Green Lantern: Emerald Twilight and Armageddon 2001. Emerald Twilight is a little easier to explain. After Mongul and Cyborg Superman destroyed Hal Jordan’s home of Coast City in Reign of the Supermen, Hal was driven into a delirious rage, determined to use the power of his ring to restore the city and everyone in it to life—even if that meant destroying the entire Green Lantern Corps in order to fully channel the Central Power Battery on Oa. In doing this, Hal transformed into the villain Parallax and set upon shaping the universe to his cosmic will.

Okay, that’s the easy part. Now, let’s explain Armageddon 2001. In 1991, a new time traveling hero named Waverider arrived in the DCU from fifty years in the future to prevent a superhero massacre by a figure known only as Monarch, which would occur in ten years’ time and lead to the downfall of mankind. Most troubling was that while Monarch’s identity was unknown, it was certain that he was one of the modern-day active heroes.

Now, according to Armageddon penciler Dan Jurgens—who, later, would go on to write and draw Zero Hour—at the time the event started, it was planned that Monarch would ultimately be revealed to be Captain Atom. But thanks to some premature leaks on the ultimate plot twist, Monarch’s true identity was changed in the middle of development to be Hawk, of the super team Hawk and Dove—despite the fact that this would contradict Hawk and Dove’s prior eliminations as suspects in the tie-in Hawk and Dove Annual. Hawk’s transformation into Monarch is the result of a self-perpetuating paradox, when Monarch kills Dove before Hawk’s eyes, driving him to become Monarch himself. The prophesied Armageddon is prevented when Monarch and Captain Atom battle each other through time in Armageddon: The Alien Agenda, leaving Monarch’s fate unknown at its conclusion.
 

The Hour Upon Us

The events of Zero Hour are predicated on Monarch, returned to the present, confronting his old nemesis Waverider and absorbing his temporal powers—thereby taking on the new identity of Extant, Zero Hour’s central villain…at least, at first. Extant begins manipulating the timeline to his will, which causes some troubling new contradictions to arise in a transforming timeline. Batgirl apparently returns, a Barbara Gordon who was never shot by the Joker. The cloned modern Superboy crosses paths with a teenage Clark Kent Superboy who never was. Triumph, a hero no one was aware even existed before, emerges as one of the founders of the Justice League. Across the published DC titles at the time of Zero Hour, the heroes of the DCU are forced to contend with a fluctuating timeline on their own terms, before joining forces in the event proper to confront the figure manipulating the timeline to his own ends. If he isn’t stopped before he can remake the universe in his image, it could mean the end for all of them.

The battle against Extant is not without casualties. JSA members Al Pratt, the first Atom, and Rex Tyler, the first Hourman, are killed in the attempt. Many other JSA members are left aged by the battle. But in Extant’s defeat, his partner in crime and the true mastermind behind the crisis is revealed. That’s right, Parallax is back, baby!

An emotional battle with the heroes of the DCU and a final blow struck by his former best friend Oliver Queen brings Parallax down, but not before he can snuff out the spark of the universe—one which is rekindled by neophyte superhero Grant Emerson, the original Damage (shoutout to my Grant Emerson fans reading this). In restoring the Big Bang, and Extant and Parallax defeated, the universe is set back as it once was.

Well, almost. As with the aftermath of Crisis on Infinite Earths, some residual effects from resetting the entire universe have altered the timeline in a way that conveniently allows for a more streamlined continuity. Nice job fixing it, hero!
 

After Hours

The final issue, Zero Hour #0 (the miniseries was numbered backwards, like a countdown), ends with a foldout timeline which realigns the entire history of the DC Universe with an updated relevance to the ongoing titles of 1994. Like History of the DC Universe before it, it’s an interesting snapshot of what events were considered pressing and important at the time of publication—like clarifying when Doctor Mist showed up, which would be relevant for all fifteen issues of Primal Force that followed.

One of the most beneficial effects of Zero Hour was “Zero Month,” a month-long period where every DC title published an issue #0, re-establishing the origins of their title characters for the post-Zero Hour timeline and providing a great primer on the hero for anyone wishing to jump in. (It didn’t hurt that a big 0 on a cover was like catnip to a ravenous speculator’s market at the time, either.) The Legion of Super-Heroes titles took the opportunity for their first complete refresh since the Silver Age. To this day, Legion fans, when discussing their favorite Legionnaires, often distinguish between “pre-Zero Hour” and “post-Zero Hour” incarnations.

A new class of heroes would arise as a result of the event as well: a new Manhunter, Chase Lawler; a new Doctor Fate, Jared Stevens; a new Starman, Jack Knight; entirely new teams like Primal Force and Xenobrood; and even a new incarnation of the Justice League led by Captain Atom, “Extreme Justice.”

Narratively, Zero Hour would represent the lowest point in Hal Jordan’s spiral to rock bottom, forcing him to reckon with the fact that he had nearly destroyed the entire universe just for a chance to undo the tragedy he had witnessed and caused in the past. It’s a reckoning which drives him to make the ultimate sacrifice in the next event following Zero Hour, The Final Night—remembered by some (me) as one of the finest events DC has ever published.

Like many events which followed, Zero Hour provided an opportunity for all the creators working at DC at the time to tell their own stories on terms that would have been previously denied to them, a feature which some of the best event comics, like 2009’s Blackest Night, would later leverage to great effect. But most importantly, it established for many of us what to expect from a Crisis event. After all, it had only really happened once before at this point, and nobody was really going to do it quite like Wolfman or Pérez ever again. How could they? And it’s worth pointing out that Zero Hour is the only event in DC history that’s ever been written and penciled by just one man. Considering its scope and ambition, it’s a miracle Zero Hour happened at all.
 

The threat of Parallax has returned in the Zero Hour 30^th Anniversary Special #1 by Dan Jurgens, Ron Marz and a variety of legendary artists. Look for it now in print and as a digital comic book!

Alex Jaffe is the author of our monthly "Ask the Question" column and writes about TV, movies, comics and superhero history for DC.com. Follow him on Bluesky at @AlexJaffe and find him in the DC Official Discord server as HubCityQuestion.