The Flash: Is SPOILER the Black Flame?

The mystery of who — or what — the Black Flame killer is has been a central aspect of The CW's The Flash thus far in Season 8. Over the course of recent episodes, Team Flash has been able to rule out Jaco Birch/The Hotness as the killer, determine that Black Flame's powers are cold based rather than hot, and then last week made the discovery that the flames themselves seem to be alive rather than being a power that a metahuman is wielding. Even as bits of information begin to fall into place about the Black Flame, however, the team is still no closer to figuring out its motives or even how to stop it—until tonight. This week's episode, "Reckless" saw some interesting developments in Team Flash's efforts to stop Black Flame as well as ended on a stunning reveal of who the killer might be.

Warning: spoilers for this week's episode of The Flash, "Reckless", below.

"Reckless" centered around Frost (Danielle Panabaker) deciding to use herself as bait for Black Flame after the mysterious killer attacked her in the apartment she shares with Caitlin (also Panabaker). Realizing that because her cryokinetic powers are similar to Black Flame's, she might effectively work as bait to lure the killer in, Frost teamed up with her mother Carla to create a trap. While the trap did work, generally, it wasn't powerful enough to contain Black Flame — more specifically, after revealing that she, too, has cryokinetic powers, Carla assisted as bait for the killer but nearly died herself which prompted Frost to stop the process — leaving the killer free, but giving the team a bit more insight on how to proceed.

While the revelation that Carla has meta powers was huge and the advancement of a possible plan to stop Black Flame was a huge step forward for Team Flash, it's what happened at the end of the episode that may have just changed everything. Alone at home, Caitlin is also confronted by Black Flame. However, instead of attacking her, the killer speaks to her — using Ronnie Raymond's voice and words.

As fans of The Flash will recall, Ronnie Raymond, played by Robbie Amell, appeared in Season 1 of the series. He was believed to have been killed during the particle accelerator accident that gave Central City's metahumans their powers, but it turned out that Ronnie had actually been fused with Professor Martin Stein (Victor Garber). The pair eventually became co-hosts for Firestorm — and were able to eventually separate, which allowed Ronnie and Caitlin to marry. Unfortunately, Ronnie died saving the city.

If Ronnie does turn out to be Black Flame as opposed to this being a manipulation in the same vein as what Chester experienced with the killer, it would be a surprising turn and one that will greatly complicate Caitlin's life. Caitlin has only recently started to date again, and it does seem somewhat likely that Black Flame will be connected to Ronnie. Amell is set to return this season and The Flash showrunner Eric Wallace has previously confirmed that Ronnie's return is part of a "complicated journey".

"It does. It does definitely because what's more inconvenient as you're starting to date than to have your ex-husband show up? I mean part of that's actually very funny. It's comedic. I'm not saying it's the funniest storyline, so please don't get me wrong, because it's not. It's obviously very dramatic and intense, but it isn't a coincidence that she starts to date, and Robbie Amell is guesting on our show," Wallace said "It's part of the complicated journey that she's going to go on to really kind of find out who she is at her core, because that's what we want to ask this season. Who is Caitlin? Oh, she's a doctor. Well, does that really define her? Okay, she's a member of Team Flash, but does that really define her? Who is she really? That's what we'll get to know in the middle of Season 8."

The Flash airs Wednesdays at 8/7c on The CW.