The CW's DC Comics-based series "Arrow" and "The Flash" go big tonight with a two-part crossover billed as a classic comic book-style collision, though it's not the first time the TV shows have intertwined. While the two shows' casts haven't intermingled to this extent before -- multiple "Arrow" cast members showing up on "The Flash," and vice versa -- the shared DNA dates back to a year ago this month, when actor Grant Gustin first appeared as "Flash" title character Barry Allen on two episodes of "Arrow."
Back then, Barry Allen was simply a forensic scientist for the Central City Police Department, with no superpowers to speak of -- but even though now he's got particle accelerator and lightning-granted super-speed and has joined Oliver Queen (Stephen Amell) in the costumed crimefighting game, Gustin said to CBR News that he doesn't think the dynamic between the two has shifted much since those initial interactions.
"To be honest, it hasn't changed that much since the last time they saw each other," Gustin told CBR at a screening event in Los Angeles. "Barry has these powers, and a little more confidence -- I think he feels like he's on a little bit more of an even playing field with Oliver, and he's not so much intimidated by him anymore. But Oliver kind of still thinks of Barry as this kid that can be in the way at times, and I think it's Barry's mission to change his mind over the course of these two episodes."
Similar to how the two shows are noticeably distinct tonally -- "Arrow" more grounded and brooding, "The Flash" more colorful and optimistic -- as are the two lead characters. Which leads to an intriguing pairing, according to Amell, who said that Barry brings a side out of Oliver that no "Arrow" character can.
"Barry has this enthusiasm and this infectious nature that is really not present with any character in the 'Arrow' universe," Amell said to CBR. "There's this one look that Oliver gives Barry when he's rambling on and getting all excited that he doesn't give anybody else. Sure enough, I gave this look a lot in episodes 208 and 209 last year, and then it laid dormant, and then within like two seconds in ["The Flash vs. Arrow," the first part of the crossover], I'm doing it again. I think their relationship is interesting. But he definitely pushes my buttons. Not in a bad way."
It's not just the series leads who are crossing over into each other's shows -- in "The Flash vs. Arrow," "The Flash" half of the crossover, Felicity (Emily Bett Rickards) and Diggle (David Rasmey) both make their way to Central City in an episode featuring Roy G. Bivolo (known in DC Comics lore by the giggle-inducing name Rainbow Raider, and now played by actor Paul Anthony). Then, in "The Brave and the Bold," the "Arrow" installment of the meet-up, Caitlin (Danielle Panabaker) and Cisco (Carlos Valdes) follow Barry to Starling and assist in a case involving another DC villain -- Captain Boomerang (Nick Tarabay), known in comics as both a primary Flash rogue and a member of the Suicide Squad (seen in "Arrow" season two).
Rickards is effectively a "Flash" veteran at this point -- along with this week's episode, she appeared in "Going Rogue," putting her at two guest spots in the eight episodes aired thus far of the first-season series.
"Felicity has to play the intermediary between the teams," Rickards told CBR of her character's role in the episodes. "She has to link them together. She's got to be the magnet."
On "Arrow" last season, fellow science nerds Felicity and Barry were positioned with plenty of romantic tension, though by the end of her first "Flash" episode, they mutually decided to be just friends -- a relationship Rickards said is fairly unique for her character, especially given the recurring "Olicity" undercurrent of potential romance between Oliver and Felicity (and rampant outcries from fans who want to see those two together).
"She's always been an advice-giver and really, really honest, but Barry's going through a new transformation in his life, and she's a friend of his," Rickards said. "Being that person, she hasn't been for Oliver to the same extent. She's kind of got to be the friend that's like, 'You can talk to me if you need to.' Being a support system."
Even in the comparatively realistic world of "Arrow," fellow Oliver Queen support team member Diggle is one of the most down-to-Earth aspects: Oliver's bodyguard, and an Afghanistan veteran armed with a gun. So for Diggle, entering the world of "The Flash" is a culture shock -- bringing drama and a healthy dose of comedy to the mix.
"Diggle's world's about to change, like everyone's else's," Ramsey told CBR. "Diggle's a soldier. He protects the people he loves by conventional means. His world changes when he meets humans that can run near light speed. And how does that effect him as a soldier? How does he protect his family when you have people like that walking the planet?"
"I think the first reaction he has to metahumans is kind of funny -- his fish out of water reactions," Ramsey continued. "That's nice, because Diggle gets to kind of be funny. But he has to come to grips with this world, and he has to in a very serious way, because it hits close to home."
Like Barry, Cisco and Caitlin both also first appeared on "Arrow" season two, but in that episode ("The Man Under the Hood"), they were fairly removed from the main interaction, rather than interacting directly with the show's leads, as they are this week.
"Cisco is the ultimate fanboy, and he has spent so much time geeking out about being a part of Barry's team and helping Barry become the hero that he is, and now to add another element to it -- helping out Team Arrow -- is huge for him," Valdes told CBR. "I expected him to literally explode halfway through the episode."
Panabaker said that in these episodes, Caitlin and Cisco experience a much more visceral realization of the type of stakes involved in vigilantism by stepping into the grittier "Arrow" atmosphere.
"I think it's a really great challenge for [Caitlin] because all of a sudden she has to deal with the reality of these situation that they keep putting Barry into," Panabker told CBR. "They send Barry out there and it's easy to sit behind your computer and tell him 'turn left, turn right, run faster, run slower,' and in 'Arrow,' she has to deal with losing someone potentially. It's really scary, and it rocks her."
Hitting just two months into the first season of "The Flash," it's clear that the shows' executive producers (Greg Berlanti, Andrew Kreisberg and Marc Guggenheim on "Arrow;" Berlanti, Kreisberg and DC Chief Creative Officer Geoff Johns on "The Flash") didn't want to wait long to mix the two together. But while there may not be another full-scale crossover anytime soon -- both shows have their own season arcs to see through -- the natural connectivity will remain.
"I don't think that it always needs to be a two-hour event, but I think some of the fun is when a character like Felicity popped up in 'Flash,'" Amell said to CBR. "That's cool. Or when Oliver popped up in the pilot of 'The Flash' for a scene. I think that making sure that these two shows are never too far apart is an important thing for us to do."
"The Flash" episode "The Flash vs. Arrow," the first part of the crossover, airs at 8 tonight on The CW. "The Brave and the Bold," the "Arrow" half of the crossover, airs 8 p.m. Wednesday on The CW.