This spring, DC Comics will put its entire line on hold to release 40 miniseries as part of their newest event, "Convergence." Each week beginning in April, DC will release ten titles set during and starring characters from the previous eras of their superhero publishing history including the Pre-Crisis, Pre-Zero Hour and Pre-New 52 timelines. Each week will also feature characters from other universes in DC continuity.

As you can tell from that description, there is a lot going on during "Convergence." So to make things simpler we combed through the solicitations, promos and information DC has released in order to break the event down to its basic components: the three core timelines involved with a brief look at the significance behind each weekly title included in "Convergence." Keep in mind this is based on information currently available and some speculation as we won't really know every detail until the event launches in April.

Related: DiDio Dishes "Convergence" Details, Talks "Multiversity" Connection

With that out of the way, let's talk "Convergence" from the returning fan favorite characters to the vital alternate reality events and beyond!

What's Crisis, Zero Hour and Flashpoint?

The three periods of time DC tapped for this event are the company's three big reboots: 1985's "Crisis On Infinite Earths," 1994's "Zero Hour: Crisis In Time" and 2011's "Flashpoint" (also known as the New 52 relaunch).

Before 1985, DC dealt with continuity problems in two ways. The first was to ignore them. The second was to turn them into alternate worlds; this way DC could wave away issues as happening on alternate Earths, freeing them to do whatever they wanted. For example, World War II heroes the Justice Society of America got spun off into Earth-Two. This explained how young heroes in the 1960s could have fought in WWII (it was a different Earth version of that hero!) and why relaunched Silver Age characters looked nothing like the Golden Age originals.

Marv Wolfman and George Perez's event "Crisis On Infinite Earths" was the first time DC streamlined its universe. Occurring on DC's Fiftieth Anniversary, the company-wide crossover "cleaned up" continuity, ending the multiverse of parallel earths and alternate heroes in favor of creating one DC Universe with one timeline. Heroes like Barry Allen and Supergirl were killed. Books were relaunched with new character origin stories. In-universe, superheroes acted as if stories before "Crisis" never existed.

However, some continuity issues remained and new problems arose over the years. In an attempt to iron those out, in 1994 DC began "Zero Hour: Crisis In Time." This was a five-issue event led by writer/artist Dan Jurgens where Green Lantern Hal Jordan went mad - calling himself Parallax and attempting to rewrite the history of the DC Universe. Ultimately, the end to "Zero Hour" effectively created a "compressed" DC publishing timeline. Now Superman officially appeared in the DCU ten years ago; characters like Hawkman that had multiple origins were merged into one verson or had their back-stories totally retconned. At the end of the event, some lingering continuity issues remained, leading to later stories like "Final Crisis." But since DC is not tapping into those realities for "Convergence," we'll skip those.

Finally in 2011 came "Flashpoint" and the New 52. In the Geoff Johns/Andy Kubert series, the actions of villain Reverse-Flash and Barry Allen create an alternate DC timeline; stories set in the "Flashpoint" timeline replaced all DC titles for the duration of the event (much like "Convergence"). The event ended with the reboot and relaunch of DC's entire publishing line. Now all superheroes officially showed up in the DC Universe five years ago. They were younger and many were radically different or completely erased. Vertigo's superheroes like Swamp Thing and John Constantine were folded into the new timeline, as were the Wildstorm Universe characters. All books were renumbered, and the new line-up included a reborn set of multiverse titles connected to the original Earth 2 concept. DC termed this the "New 52" - the timeline of today's titles.

Now that we have that context, you may want to know exactly how "Convergence" will tap into each timeline.

"Convergence" Week One: Return of the Fan Favorites

The first week of "Convergence" mini series are entirely set in pre-New 52 continuity. It incorporates characters from "Flashpoint" as well as Captain Carrot and the Zoo Crew (superheroes from a world populated by anthropomorphic animals) and the Extremists (an alternate reality supervillain team created in the '90s).

This week is primarily driven by fan reaction to the New 52. Beloved Batgirls Stephanie Brown and Cassandra Cain get their own "Batgirl" title -- fitting as many protested their New 52 exclusion, such as the fan who dressed as Steph Brown and showed up at multiple conventions to question DC about diversity and sexism. Fans were also vocally upset about loosing the wheelchair-bound Barbara Gordon, who appeared consistently in Gail Simone's pre-New 52 "Birds Of Prey." Thus during Week One Simone brings readers an "Oracle/Nightwing" book which touches on the abandoned Barbara/Dick Grayson relationship as well. The popular pre-New 52 Wally West and his family (erased by "Flashpoint") return in "Speed Force." So does Gotham City Police officer Renee Montoya as "The Question" with Greg Rucka writing the character he helped popularize during the early 2000s.

The other titles of this week mainly bring back pre-New 52 teams and iterations. The "Harley Quinn" book is a "Gotham City Sirens" reunion, celebrating the Poison Ivy/Catwoman/Harley team-up erased by "Flashpoint." "The Atom," "Justice League" and "Titans" titles all seem to touch on large status quo shifts: the death of Ryan Choi, Jesse Quick losing her powers due to pregnancy and the death of young Lian Harper. The solicit for "Batman And Robin" seemingly highlights Batman (most likely the Dick Grayson version) and Damian fighting Red Hood (most likely the Grant Morrison iteration). Finally, Dan Jurgens brings back husband and wife Lois and Clark as expectant parents in "Superman."

Week Two: An Event for Everyone

Week two takes the DCU back in time to "Zero Hour." The '90s marked the rise of the collectors market, and as a result, big event comics dominated the era. While characters from the graphic novel "Kingdom Come" and the Wildstorm heroes and villains (GEN13, Deathblow) appear in some of this week's titles, the main emphasis for "Convergence" is on big event characters and creators.

The "Death Of Superman" and follow-up "The Reign Of The Supermen" are hugely important for DC as a publisher. Millions of copies of the Doomsday Vs. Superman story were sold in 1993, and mainstream media covered the event. The following "Reign Of The Supermen!" arc capitalized on this attention, creating Superman replacements like African-American Steel and clone Superboy Kon-El. With "Death" leaving such a huge historical impact, it's a no-brainer for DC to have the original writers, Jurgens and Louise Simonson, return to their creations. Jurgens hits Week One and Simonson revisits Steel in "Superman: The Man Of Steel" in Week Two. A '90s "Superboy" story rounds out this time period.

Batman was also subject to a giant event with "Knightfall" as super villain Bane broke his back, putting him out of commission and letting anti-hero Azrael take his place. Week Two's "Batman: Shadow Of The Bat" is set in this time period, right after Batman's back is healed. "Catwoman" also picks up around here, the character donning her infamous '90s Bad Girl Art purple cat suit and thigh-high boots.

And of course while Hal Jordan/Parallax was the ultimate villain behind 1994's "Zero Hour," the '90s also introduced Kyle Rayner as the last Green Lantern. However, many know that period better for the murder of Kyle's girlfriend launching the "Women In Refrigerators" meme and discussions about women in comics. Between Hal's "Zero Hour" role and the larger comics community repercussions, including a "Green Lantern/Parallax" title is another obvious move.

The rest of the titles focus on the biggest changes to individual characters throughout the late '80s and early '90s. Conner Hawke, Oliver Queen's son and sidekick created in 1994, is back in "Green Arrow." Week Two's "Aquaman" points to the popular '90s iteration who lost his hand to piranhas and replaced it with a hook. Fat, middle-aged bureaucrat Amanda "The Wall" Waller, created as the manager for Task Force X, appears in "Suicide Squad." The popular and comedic "Justice League International" return and Keith Giffen (JLI co-creator along with J.M. DeMatteis and artist Kevin Maguire) puts his creation Ambush Bug in the middle of "Supergirl: Matrix." This last title brings back '90s Matrix Supergirl, a shape-shifting alien who transformed into the superhero and dated Lex Luthor. Keep that crazy image in your head as we move on to...

Week Three: An Age of Bronze Multiverse

"Convergence's" third week stands firmly in Pre-Crisis mode, focusing for the most part on Earth One (the prime DC Earth during the company's classic period). These titles are mostly set in the "Bronze Age" period that spanned from 1970 to 1985. The Tangent Universe characters ('90s DC imprint starring alternate versions of their biggest superheroes) will be popping in, as well as Jack Kirby's 1972 apocalyptic "Kamandi" comic and the Red Rain vampires (a 1991 "Elseworlds" alternate reality story). But the focus remains on the pre-Crisis characters that once defined DC.

The two biggest creators and comics in Week Three are Len Wein on "Swamp Thing" and Marv Wolfman on "New Teen Titans." Wolfman's Titans were an immensely successful and popular group for DC, introducing fan favorites Starfire, Cyborg and Deathstroke alongside the likes of Donna Troy and Kid Flash. Wein was the co-creator of Swamp Thing and left the book early in its history, so letting these two return to their creations is another clear choice.

The rest of the titles highlight the best-known (or most debated) iterations of pre-Crisis superheroes. "Wonder Woman" seems to be set just after the early '70s de-powered mod-suit version of Diana Prince (a controversial version labeled sexist by feminist Gloria Steinem). The 1984 "Justice League of America" team known as Justice League Detroit is also back, DC's ill-fated attempt to create a young superhero team book. The team was eventually disbanded, though DC Chief Creative Officer Geoff Johns has since returned JLA member Vibe to the New 52.

Less contentious is the classic Barry Allen version of "The Flash," an important inclusion as the 1961 "Flash Of Two Worlds" story helped DC create the idea of a multiverse. "Hawkman" has the titular Thanagarian protagonist and Hawkgirl dealing with the 1985 "Shadow War Of The Hawkmen" story and characters from "Kamandi." "Green Lantern Corps" brings pre-Crisis Hal and his replacements Guy Gardner (who appeared in 1968) and African-American John Stewart (created in 1971) together. "Batman And The Outsiders" began in 1983 as a misfit team assembled by Batman, introducing heroes like Katanna and Geo-Force, who was also tied to the Teen Titans. In "Adventures Of Superman" Supergirl sports her 1984 headband, and it looks as if this story is about the repercussions of "Crisis."

The one mini series that doesn't quite fit this week's theme is "Superboy And The Legion Of Super-Heroes," a Silver Age title. The Legion is not totally out of place, however, as they would experience a Bronze Age renaissance in the hands of Paul Levitz and Giffen during their popular Legion versus Darkseid storyline "The Great Darkness Saga."

Week Four: DC's Timelines Collide

The final week of "Convergence" takes us all over the multiversal map with nods to the Bronze, Silver and Golden Ages. It also incorporates companies DC either licensed or swallowed whole: Fawcett Publishing, Quality Comics and Charlton Comics. Meanwhile, the Qward Universe (antimatter universe, home of the Anti-Monitor), steampunk Gotham, "Red Son" graphic novel and One Million Universe (a version of the DCU set in the 853 century) enter a few stories. Ultimately, this week has many competing worlds due to the nature of the time period.

Perhaps most importantly, this week's inclusion of the "Crime Syndicate" of Earth 3 and the "Justice Society of America" titles is significant as the teams marked the first multiverse Earths created by DC. They also mark DC's early use of the word "crisis" when in 1963 the two-part story "Crisis On Earth One" and "Crisis On Earth Two" crossed the JSA with the Justice League. The Crime Syndicate would join the fun in 1964's "Crisis On Earth Three."

Additionally, "Blue Beetle" depicts Charlton heroes Blue Beetle, Captain Atom and the Question and should be extra familiar to readers as Alan Moore and Dave Gibbons used variations of them in "Watchmen." Week Four also has Fawcett's Captain Marvel in "Shazam" -- the character was officially renamed Shazam for the New 52 and seems to retain that name in these solicits. Earth X hosts "Plastic Man And The Freedom Fighters," characters from Quality Comics who younger readers may know from the 2006 Justin Gray/Jimmy Palmiotti "Uncle Sam And The Freedom Fighters" revival.

"Action Comics" and "Detective Comics" round out the important titles to Week Four as they were DC's oldest ongoing books and seem to tackle Silver Age Helena Wayne and Bronze Age Power Girl. "Infinity Inc." is the JSA version of the Teen Titans, made up of JSA heirs and offspring. The Golden Age Seven Soldiers of Victory, appearing in "World's Finest Comics," were DC's second superhero team (the first being the JSA).

The final book, "Booster Gold," is another timeline outlier. Created by Dan Jurgens in the '80s, Booster Gold was originally a disgraced athlete who stole superhero gadgets and traveled back in time to make a quick buck fighting crime. Because of his nature as a time-traveler, Booster appears to be one of the few characters able to tell when the DC timeline is tampered with. And just as the last "Booster Gold" ongoing laid the groundwork for "Flashpoint," Jurgens recently noted in a CBR interview that the alternate reality teases placed in his recent "Futures End" one-shot would pay off here.

So what does "Convergence" mean to DC as a whole?

While the event is happening to cover DC's real world move from New York to Burbank, the emphasis being put on the three times DC rebooted their comics and the ongoing titles ending in March suggest this will impact the DCU moving forward. The most extreme outcome would be using "Convergence" as another reboot. This could either be a soft reboot -- DC reintroducing popular characters or status quos back into the New 52 timeline -- or a hard one, using "Convergence" as a "Flashpoint"-level event to relaunch the entire DCU. However, as DC has reintroduced or reinvented many of the characters fans want to see in the New 52 (Wally West, Steph Brown, etc.) and as it has been only five years since "Flashpoint," this is debatable.

A second outcome could be that DC begins relying on the multiverse again. Since "Crisis On Infinite Earths" every decade or so DC has had to reboot their titles in order to maintain one consistent timeline, whether that be a soft reboot or taking an axe to their books. Reinstating the multiverse as an important component of the DCU may allow DC to bring back characters and timelines people love or tell new stories without impacting the "main" DC timeline and having to reboot yet again.

The third outcome of this event might just be an official policy of loosening continuity. We can see this already taking place in the Batman line of books. Each title is essentially set in it's own genre and largely ignores events in the flagship "Batman" comic, publishing tie-ins whenever they have to address a continuity change in status quo. It is easy to see the Bat books as a template for the rest of the DCU. DC could easily green light more self-contained books, put out weekly series or events that satisfy continuity hounds and keep the multiverse on hand for titles like "Earth 2" or popular media tie-ins like "Batman '66." Whatever the case, April and May's "Convergence" event is going to be an interesting time for DC -- though hopefully, no longer a confusing one.