Welcome back to The Hollywood Reporter's weekly DC TV Watch, a rundown of all things DC Comics on the small screen. Every Saturday, we round up the major twists, epic fights, new mysteries and anything else that goes down on The CW's Arrow, The Flash, Legends of Tomorrow, Supergirl and Black Lightning and Fox's Gotham. This week, THR breaks down that epic milestone 150th episode of Arrow along with this week's outings of The Flash and Black Lightning. Note: Supergirl and Gotham did not air new episodes this week, but Gotham did host a Q&A panel at the 2019 Winter Television Critics Association press tour.

Arrow

The big news: To celebrate hitting a milestone of 150 episodes, Arrow became a documentary for part of the big hour, highlighting the rise of vigilantes in Star City thanks to Oliver Queen (Stephen Amell) becoming the Green Arrow. But it was the final moment's twist that showed the reason behind the structural twist: Mia (Katherine McNamara) was watching the "banned" footage in the future timeline with her ally, Connor Hawke, aka John Diggle Jr. (Joseph David-Jones), reprising his role from the Legends of Tomorrow dystopian future episode in a surprise twist.

What it means: Despite the Legends saving Star City's future in that early season one episode, Diggle's (David Ramsey) son still found his way to the Team Arrow bunker in a different kind of dystopian future. While it's not known yet if Connor has taken up the Green Arrow mantle in this timeline, it's clear that he and Mia are working together to do ... something. Mia's thoughts on vigilantes "getting what they deserved" is clear, but does Connor agree with her? What happened to his father? This is the only glimpse of the future fans got in this week's episode, but the implications are huge. Mia and Connor wanted to find the bunker for a reason, and the documentary gave them all the clues they needed to locate it. But now that they're inside, are they going to use it to help reunite Team Arrow in the future, or get revenge on all the remaining vigilantes for "destroying" Star City? No matter the outcome, using the documentary to further the future storyline intrigue was a clever call, as it gives real creative weight to the structural twist. Plus, aligning Mia and Connor, two characters with rich comic book histories, is a nice payoff for long-running stories woven throughout the entire series.

Other noteworthy moments: The documentary also brought back some familiar and fan-favorite faces for talking-head interviews that the director had banked for years. Because Oliver recently outed himself as the Green Arrow and became deputized by the SCPD, the documentary received new funds to finally get finished due to reignited interest. That's why interviews with beloved but late characters like Quentin Lance (Paul Blackthorne) appeared, along with characters who haven't been seen or heard from in years, like Thea (Willa Holland), Sin (Bex Taylor-Klaus), Rory Regan/Ragman (Joe Dinicol), along with Legends' Sara Lance (Caity Lotz) and The Flash's Barry Allen (Grant Gustin), who had one of the episode's highlights as he fails to lie smoothly about not knowing Oliver's secret identity.

And behind the scenes while the documentary cameras weren't rolling, William (Jack Moore) came home from boarding school with a chip on his shoulder and a secret. He resented his family for "abandoning" him at school over the holidays whereas Oliver and Felicity (Emily Bett Rickards) simply thought they were protecting him from Diaz (Kirk Acevedo). His trouble at school on the surface appears to be from his anger, but could this perhaps be from his struggle with his sexual identity? Fans know that the adult William is an out gay man, but this younger version has not come out yet (or may not even know/understand his own feelings yet). This is the perfect opportunity for Arrow to further LGBTQ representation in the comic book genre by telling his coming out story in a responsible way, if that is the reason behind his issues with his boarding school performance.

Gotham

The big news: David Mazouz will in fact don the iconic cape and cowl as a fully realized Batman in the Gotham series finale, albeit with a slight twist.

What it means: While presenting a farewell to Gotham panel at the Television Critics Association press tour, the showrunners and stars revealed some intel on the series finale, including that the actor who has been playing young Bruce Wayne will be the one underneath the mask during the 10-year flash forward ... but only sometimes. "Is David Mazouz in the suit at the end? This is going to sound evasive but I’m going to say yes and no," executive producer John Stephens said. "David is a strapping young man, but our Batman suit is built for someone who’s 6’4. But the face under the mask and voice is David's." Fans will hear Mazouz's "Batman growl," but due to production logistics the actual body will be someone else's.

Other noteworthy moments: During the panel, the producers and stars also revealed some details about other characters in the series finale's 10-year time jump. Aging up the characters didn't take much: Jim Gordon (Ben McKenzie) will have his iconic mustache, as McKenzie quipped, "They only had to add one thing to me," pointing to his upper lip. Penguin (Robin Lord Taylor) will be wearing a fat suit. And Stephens confirmed that Selina Kyle (Camren Bicondova) will be a fully realized Catwoman as well. But will Jeremiah Valeska (Cameron Monaghan) finally be the Joker?

"Am I going to be the who? I'm sorry?" Monaghan joked. "I can tell you but I'd have to kill you. That's one that's sealed." Stephens then elaborated, "We wanted to create a canon that's both inside the canon and outside the canon. All the iterations that Cameron has played, Jerome then Jeremiah then a third that no one has seen yet, if he's not the Joker, then he's someone that does provide the origin story for who will."

During a short video presentation before the press tour panel began, footage showed Jeremiah falling into a giant vat of neon-green liquid, hinting that while his origin story of becoming the Joker has not yet been fully realized, Gotham will be taking a page directly out of the comic book source material for his storyline. Executive producer Danny Cannon revealed that in the last half of the season, they're really going for it in terms of comic book insanity. "It was agony holding back because we had a clear idea of where everyone was going," he said of earlier seasons. And McKenzie promised that they didn't leave anything out of the final run. "If we don’t do them now, we’ll never get to do them, so we better do them," he said about story ideas they didn't tackled in previous seasons.

And while Gotham has truly gone for it when it comes to bringing some of the more wild comic book characters to life throughout the series, there's one villain that never seemed to fit within this gritty, grounded world: Killer Croc. “It would have been jumping the shark to do a seven-foot crocodile,” Cannon said. But then Stephens added, “We’re never going to do Killer Croc, yet there’s a character we’re doing that really looks like Killer Croc." So keep your eyes peeled for that outrageous addition to Gotham's Rogues Gallery in the final few episodes.

The Flash

The big news: While the rest of Team Flash continued to brainstorm ways to take down Cicada (Chris Klein), it was actually Iris (Candice Patton) who pushed the case along the most in this week's episode, all by using her reporting skills and bravery.

What it means: As Barry and Ralph (Hartley Sawyer) learned some lessons on how far they'll go and what lines they'll cross to defeat Cicada, Iris found his hideout and even managed to incapacitate him for a moment. She hunted down leads that led her straight to his cousin's house where he was hunkering down, and while she almost made it out without blowing her cover story he wised up to her lies. He tried to attack her, but she bravely fought him off and even managed to stab him with a pen right where the dark matter injury on his chest was. He fell down in pain, and she got away, with some of his blood to boot. Now Team Flash can engineer the meta cure specifically for his DNA. Talk about a win!

Other noteworthy moments: This week's episode was particularly Sherloque (Tom Cavanagh) heavy, which maybe isn't the best idea when it comes to yet another wacky version of Wells (remember that Council of Wells?). But this hour did reveal that all seven of his failed marriages were to alternate Earth versions of the same woman, Rene Adler (Kimberly Williams-Paisley). Nora (Jessica Parker Kennedy), knowing that Sherloque was on to her secret of working with Eobard Thawne (also Cavanagh), decided to distract him by helping him meet this Earth's version of Rene. He instantly fell in love but discovered that she might be a meta herself. Freaked out that Cicada could target and kill her in his quest to kill all metas, Sherloque forgot all about looking into Nora's secret and renewed his efforts into the Cicada case to protect his new love. Smart move on Nora's (and Eobard's) part, but hopefully the introduction of a love interest will help ground Sherloque's antics moving forward.

Black Lightning

The big news: Grace Choi's (Chantal Thuy) metahuman powers emerged once more, forcing her to run away to keep her powers a secret from Anissa (Nafessa Williams).

What it means: While comic book fans know that Grace comes from a long line of Amazons, her powers seem to be taking a different form on the show. Black marks keep appearing on her skin, morphing and then disappearing. In the comics, Grace has superstrength and healing, but no mention of anything changing on her skin. Could this be the show's way of adapting her tattoos from the comics and transforming them into a new kind of power? Even though she ran away from Anissa, this definitely won't be the last time Grace is seen on Black Lightning. Her destiny as one of the main heroes of The Outsiders, plus her relationship with Anissa, means that the show has only scratched the surface on her potential so far.

Other noteworthy moments: Jennifer (China Anne McClain) and the rest of the Pierce family helped Khalil's (Jordan Calloway) mother organize his funeral. This was definitely the moment Jennifer needed to mourn her boyfriend, and based off promos for the next episode, she'll be turning to the anger stage of grief as she seeks revenge on Tobias (Marvin "Krondon" Jones III). Is that mission finally going to help her focus her control on her powers? This could be the step she needed to take to become Lightning after her long struggle with her abilities all season long.

Looking ahead

While Gotham took this week off, next week's return sees Shane West's Eduardo Durance finally becoming the iconic version of Bane, mouthpiece and all, that fans have been expecting since news of his casting broke this fall.

Note: Supergirl airs Sundays; Arrow and Black Lightning air Mondays; The Flash airs Tuesdays; and Legends of Tomorrow returns in April on The CW. Gotham airs Thursdays on Fox.