Spoilers follow for those of you who haven't caught up with the season finale of DC's Legends of Tomorrow.

If you watched The CW's season finale of DC's Legends of Tomorrow last night, then you're aware that some pretty big additions are in store for season two. As Allison Keene mentioned in her finale recap, the title team had their hands full with the first season's big bad, but ultimately dealt with him in as savage a way as possible. With that bow neatly tied, a new wrinkle was added to the show by way of a brand new character making his appearance at the episode's end.

That character, played by Patrick J. Adams (Suits), introduced himself as Rex Tyler (a.k.a. Hourman), a member of the Justice Society of America who was sent back in time by none other than Mick Rory in order to save the lives of all the Legends. That's a big nugget to drop on fans at the end of an episode, let alone the end of a season. But while longtime comic book fans may have an inkling of what's coming in Season 2, the average viewer was probably left a little confused. So let's clear some things up.

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Image via DC Comics

THR caught up with Marc Guggenheim to talk about what the arrival of Hourman and the JSA means for Season 2 of Legends of Tomorrow. He had this to say:

"With his final words in the finale, he planted a pretty deep flag about where we're headed in season two, which is not just introducing Hourman but introducing his teammates in the Justice Society of America. For comic book fans, everyone knows the Justice Society is really the precursor to the Justice League, so it's a pretty big move in our DC universe here on TV."

Though there is much to bemoan about the gulf that separates DC Comics and Warner Bros.' cinematic universe from its TV-verse, the introduction of the JSA is actually a pretty cool move for the TV side. Today, it's less well known than the Justice League, which is of course getting its own feature film(s) treatment. However, the JSA is packed with interesting and iconic heroes that have decades worth of comic book storylines and mythology. Guggenheim continued:

"God bless both the studio and the network. They've never said, 'This is too big. You can't do it.' They have often said, 'Jeez, this is so big, how are you going to do it?' They say that a lot. They're always asking us how the hell we're going to pull something off. Inevitably, our answer is, 'We literally have no idea. But we'll figure out a way.'"

Personally, I'm still hoping that the DC TV braintrust figures out a way to pull off the "Blackest Night" storyline, but with Green Lantern tied up in the movie-verse, that's probably never going to happen. So while the Green Lantern Alan Scott, who was rumored to be making an appearance in the Legends finale before the arrival of Rex Tyler squashed that for good, may not be checking in for the JSA, there are plenty of other heroes who could, and should. Some you've already met.

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Image via DC Comics

After a bit of retooling in the DC Comics world, the JSA became the league of superheroes who defended Earth-2 against supervillainy. There have been plenty of references to this group on The Flash, with the huge mural in the Earth-2 Central City police station being the most notable one. The marketing for Legends of Tomorrow also strongly hinted at the arrival of some of the JSA members a few months back. We've just met Hourman, but the interesting thing is that we have already been introduced to other members of the original roster: Jay Garrick/The Flash, Carter Hall/Hawkman, Terry Sloane/Mr. Terrific (a Golden Age version of Michael Holt's eventual hero), Ted Grant/Wildcat, and yes, even Dinah Drake/Black Canary.

If you have lightbulbs going off in your head about where we've seen these characters before and which shows they're on, then the planned four-series cross-over event special for The FlashArrowSupergirl, and DC's Legends of Tomorrow should make more sense with the JSA involved. Outstanding members of the team, like the aforementioned Alan Scott, Jim Corrigan/Spectre (who was actually introduced on NBC's Constantine), Wesley Dodds/Sandman, Kent Nelson/Doctor Fate (whose helmet was also teased in Constantine), Al Pratt/Atom (a Golden Age comic book hero who inspired the Silver Age creation of Ray Palmer's Atom), and more may or may not show up in some capacity. Sandman probably has the best chance of happening since the marketing team already teased his appearance, though it could be something like the very brief on-screen appearance of DC Comics hero Sgt. Rock during the finale. Regardless, there are plenty of characters to go around.

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Image via DC Comics

Whoever comprises the JSA, it's safe to say that they'll be assisting the Legends in managing the timelines in Season 2. Guggenheim talked about that challenge as well:

"One of the other big things we've done in the season finale is we planted another flag in the form of Rip's [Arthur Darvil] statement. Because the Time Masters are essentially gone and the Legends have destroyed the Oculus, that all means that someone else has to do the job of the Time Masters. Our Legends take that on as their new responsibility. It's sort of like, you break it, you buy it.   "That's really exciting to us, that our team of Legends, our misfits, are going to be responsible for the preservation of the timeline and protection of history,. As we've seen, our team, our guys are not always the most responsible people around so maybe time has got some new troubles. But it will provide a lot of fodder, a lot of fun story for season two."

It sounds like the writing team is attempting to right the ship for Legends' follow-up season by firming up the in-show rules for time-travel and, perhaps more importantly, bringing a more satisfying villain into the mix:

"The season two big bad is actually not going to be the [alien race of] Thanagarians. It's going to be something else entirely. All I'll really say about the nemesis in season two is Vandal Savage looks like a walk in the park compared to what the Legends will be facing. This will be a much, much bigger threat. I'm going to leave it at that because when we do reveal it, it's going to be pretty big. People will be asking, 'Vandal who?' once they get the full picture of what our team is up against. It's going to be way bigger than what you can even imagine, I can guarantee it."

Any guesses for just who that might be? Let us know your thoughts in the comments!

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Image via DC Comics