"The Flash" and "Arrow' tie their shared universe even tighter this week with the second annual crossover between the shows, a two-part installment introducing Hawkgirl (Ciara Renee, who's already appeared on "Flash" as civilian identity Kendra Saunders), Hawkman (Falk Hentschel) and immortal villain Vandal Savage (Casper Crump). It's a prelude to the upcoming "DC's Legends of Tomorrow" series, and with production schedules of three different shows to juggle, it was about as tricky to pull off as you might guess.
"I don't think it's possible to overstate the incredible amount of difficulty it was for just about everyone involved," Marc Guggenheim, "Arrow" co-showrunner and "Legends of Tomorrow" executive producer, told a group of reporters including CBR News during a press event Monday at The CW headquarters in Burbank. "Certainly, the actors being asked to shuttle from literally one set to two other sets, often times in the course of a single day, to the crews of the three different shows, to the ADs -- these guys put together schedules that were like higher mathematics."
"It was an acting marathon," added Hentschel, who had already started production on "Legends" when filming the crossover episodes. "It was a whirlwind, but it was really amazing to see it come together. When [the executive producers] all told me about this, at first I was like, 'How is this going to happen?'"
There was a race to the finish line on the post-production side as well, with visual effects completed just a couple days before this week's airdates. But it should all be worth it for "Flash" and "Arrow" fans, who will witness a true two-parter this week, rather than last year's crossover, which was more two loosely connected standalone episodes featuring characters from both shows.
"With last year's episode, obviously it was the first time we'd ever done it, and we were very conscious of not everybody who was watching 'Flash' was watching 'Arrow' and vice versa, so we wanted to make sure they both were self-contained episodes," "Flash" showrunner and "Arrow" and "Legends" executive producer Andrew Kreisberg told the assembled press. "This time around, given the success that we've had previously, and how people are viewing this as much more of a collective, shared universe, we felt emboldened, and our partners at CW and Warner Bros. were more supportive. We were able to have a two-hour, true event with one story and one villain, one storyline, and not having to worry so much about the mechanics of how it would air."
"The Hawks and Vandal Savage deserve a two-hour introduction," said DC Entertainment Chief Creative Officer Geoff Johns, a man very familiar with Hawkman and Hawkgirl from writing stints on DC Comics like "Justice Society of America." "They're big characters."
The crossover episodes -- collectively promoted as "Heroes Join Forces" -- are a direct prologue to "Legends of Tomorrow," which debuts Jan. 21 on The CW. But don't look for the full cast of that show in these episodes -- there's no Atom, White Canary, Firestorm, Captain Cold or Heat Wave present, as the focus is on detailing the 4,000 year history between the Hawks and Vandal Savage. Along with the usual fun of seeing Team Arrow working alongside the S.T.A.R. Labs crew, of course.
"The studio and the network were asking for us from the very beginning of the year, 'Which characters from "Legends" are going to be in the two-hour?' We wanted to have a couple, but not all," Greg Berlanti, executive producer of all three series, said. "It also felt right that we would use the characters that we hadn't introduced on the individual series yet, with the exception of Rip Hunter, who's saved for the pilot of 'Legends.'"
Hentschel, who already had some experience with comic book-based TV after a guest spot on a "Marvel's Agents of S.H.I.E.L.D." episode in 2014, is especially looking forward to fully exploring the unique dynamic of the continually reincarnated Carter Hall and Kendra Saunders, and the complications that creates.
"They're, in my mind, a bickering old couple," Hentschel said. "He's gone through 4,000 years of loving her, and having her love him back -- and she doesn't know about it yet, so there's always this fun dynamic of him being like, 'You'll love me, it'll be good, I've seen it.' I think underneath it, too, I'm terrified always of losing her. Imagine you've seen everybody that you know die. It's pretty lonely, and here's that one person that is always constant."
"He remembers loving Kendra, and he remembers all the adventures they've had," Kreisberg added. "Not just the bickering, but he remembers all the fun they've had. Now, he's staring at this woman who's looking at him like he's crazy."
While that's a fairly complex relationship, Hentschel had a simple answer to how he enjoys appearing in the Hawkman costume, which is comic book-y even by "Flash" and "Arrow" standards. "It's awesome. I was like, 11 years old, just standing there -- it's like a dream come true. You've got a costume that's fit for you, and you feel really good about life. And then you get the helmet on -- it's awesome!"
"Legends of Today," the "Flash" half of this year's crossover, airs 8 tonight on The CW. "Legends of Yesterday," the "Arrow" installment, airs 8 p.m. Wednesday on The CW.