Black Lightning 's Cress Williams breaks down those finale twists and surprise cameos

Warning: This article contains spoilers from the season 3 finale of Black Lightning, which aired Monday night.

Black Lightning gave Damon Gupton's Chief Bill Henderson a heroic send-off.

In the CW superhero drama's season 3 finale, Gupton's last as a series regular, Henderson crept up on some of Gravedigger's soldiers and took them out before they could shoot Black Lightning, but then one them let off a shot as he died that hit Henderson right in the chest. Hearing the shots, Black Lightning/Jefferson Pierce (Cress Williams) rushed over and found his best friend on the ground with a gaping wound in chest and got a chance to say goodbye before he perished. At this point, Williams isn't sure what the writers have in store for next season, but he suspects and hopes this will have a major effect on his lightning-powered hero going forward.

"I hope that we carry it through [and] it's not something we just drop, and fast forward to the next season, and it's almost like it's just forgotten, aside from a line here and there," Williams tells EW. "Because real life, [when] you lose people like that, it's not something that just goes away. It is something that affects you and carries through. My guess, if I was going to be writing it, is that I think it would make Jefferson even more cautious and scared of anybody else doing this stuff, his daughters included. I think he'd be a lot more, I would hope, more cautious, and almost that would be kind of a hurdle to get over in the next season, that he's almost too cautious because he lost someone."

After Henderson expired, Black Lightning entered the Pit for his final showdown against Gravedigger (Wayne Brady). With Lynn's (Christine Adams) help, Jefferson neutralized Gravedigger's extra powers and defeated him, but then the Pit started to self-destruct. Jefferson wanted to help his great-uncle escape, but Lynn said there was no time and they left him behind to die in the blast (or so they thought).

With the Markovian invasion crushed, the Pierces traveled to Gotham City and testified about the ASA's illegal experimentation on the people of Freeland at a hearing. Right before taking the stand, though, Lynn popped some glimmer, indicating that her struggle with addiction is far from over and will carry on into next season. According to Williams, though, the season didn't originally end that way.

"I'm excited about doing [an addiction story] the right way. That end went through quite a few different rewrites, and I was happy with what they settled on, because I think in maybe even one or two of them, she didn't pop in a Green Light, and we just kind of moved on. Anybody who knows about addiction knows that it's not kind of like, 'Oh I quit now,' and it's just easy. I think people often fall off the wagon, and it's an uphill battle, and there are two steps forward and three steps back in the process. so I was really happy that we did that, and that it seems like we're not going to just gloss over it."

He continues: "Ultimately, I think we want to see her overcome it, but I think she's got to earn it. And I think we as a show have to earn it. If we had just ended the season and we never hear about Green Light ever again, or the Glimmer that she was taking, then it doesn't feel real. So I'm glad that we're going to go into it further, and I hope we continue to kind of ground it in realism."

That final hearing-scene featured a couple of other reveals. First, Tony Isabella and Trevor Von Eden, who co-created the character Black Lightning, had cameos as judges at the hearing. "They were like kids in a candy store, to be able to be in a scene," says Williams of shooting with the comic book veterans. "It's always interesting when you're working with non-actors. You give them all the positive energy you can because even though they only had a couple of lines, you could still see the nervousness on them. So, that was funny."

Furthermore, and more importantly, Gravedigger survived the Pit explosion and attended the hearing in disguise. Williams believes fans should be "extremely worried" about what that means for the Pierce family in season 4. "We know that Tobias is obviously still around, and he's always trouble. But then to add this other person who we don't know is still alive at that point and has this kind of maniacal grudge against the United States and against the Pierce family. And he's super-powered. And even without the extra superpowers, that power to be able to just tell people what to do and they have to do it, that's crazy, that's bananas. So, I think we're in trouble, mainly because of the secrecy, because of the fact that we don't know," he says.

With the Markovian story arc complete, Williams suspects the show will get back to basics in season 4: "At least at the start of the season, I feel like it's going to scale back a bit."

Black Lightning airs on The CW.

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