Warning: spoilers ahead the fifteenth episode of Gotham Season 4, called "The Sinking Ship, The Grand Applause."
Gotham has no shortage of villains by this point in the fourth season, and most episodes feature more than one bad guy in the mix. That said, the big bad of Season 4 has arguably been Sofia Falcone, who swooped in to take over her father's former crime syndicate and won control over the Gotham underworld. She seemed unstoppable, having gotten her hands on Martin, landed Penguin in Arkham, got leverage on Jim, and recently had Lee's hand bashed in as a power play. "The Sinking Ship, The Grand Applause" proved that even Sofia wasn't beyond being soundly defeated, and she met an unceremonious fate that may have set the stage for another big bad to return.
"The Sinking Ship, The Grand Applause" was something of a melee as some of the biggest characters of the series ran around, trying to further their agendas and making alliances on the fly. After a major shootout ended with Jim bleeding out on the floor, Sofia was on the verge of executing her former lover. She was only stopped when Lee shot her in the torso from behind. Not satisfied with simply wounding Sofia, Lee went for a headshot and seemingly killed Sofia with a bullet to the brain.
Now, because this is Gotham, a bullet to the brain isn't necessarily enough to kill characters, and the episode revealed that Sofia survived her injuries but was left in a coma. Assuming she doesn't end up dumped in a mysterious swamp, she probably won't be resurrected as a female Solomon Grundy, and it's difficult to imagine how exactly she could come back from looking super dead. Still, Gotham would have killed her off if her purpose in the story was entirely spent. She may come back at some point, even if she's quite different.
She is gone for the time being, and her departure coincides with the return of another villain: Ra's al Ghul, who was supposed to be dead after Bruce Wayne took him out with his own dagger. Given that Ra's al Ghul is a legendary bad guy of Batman lore and most versions of Batman are known for their refusal to kill, the odds were always that Gotham was going to bring Ra's back. The questions were when and how it would happen. Well, it seems that the "how" is via his connection to Barbara Kean.
When Ra's said goodbye to crazy Babs earlier in the season, he did something to her that she definitely wasn't expecting and didn't entirely understand. They weren't even physically touching, but he still managed to do something to her. Gotham went quite a while without revealing the effects of whatever he did. In "The Sinking Ship, The Grand Applause," we finally saw something happen. Barbara was suffering from terrible headaches throughout the episode, to the point that she could barely stand upright or listen to conversation. It wasn't until she seemed to hallucinate Ra's walking toward her in her club that it became clear he had something to do with what was happening.
On the one hand, Ra's was killed earlier in Season 4. His physical body was mortally wounded. Even if villains like Jerome and Butch were able to come back from the dead in their own bodies, something tells me Ra's' return won't be simple. Judging by how Barbara was reeling from pain in her head, the fact that nobody else could see Ra's, and the twist when his face melded with her own, I'm guessing that Ra's somehow transferred his consciousness into Barbara in the event that Bruce did indeed kill him. That doesn't answer the question of how Alexander Siddig will reprise the role after Ra's was physically killed, but we can bet that Gotham will find a wonderfully weird way to do it.
You can catch new episodes of Gotham on Thursdays at 8 p.m. ET on Fox. For more viewing options, be sure to take a look at our midseason TV premiere guide and our 2018 Netflix premiere schedule. If you're not up on which shows have gotten the axe this season, check out our rundown of TV renewals and cancellations.