This article contains spoilers for DC's Legends of Tomorrow coming from the events of Crisis on Earth-X. If you have not watched the full Arrowverse crossover event and don't want spoilers, look away.
Well, we knew it was coming. Probably long before this season. When you have an incredibly talented actor like Victor Garber, you can only expect him to be around for so long before he is drawn back to the live stage. So, I've kind of been expecting this since her first appeared as Professor Martin Stein on the Flash back in the shows first season. As half of Firestorm, he was teamed with Ronnie Raymond (Robbie Amell) for part of the season but that ended with the season finale. After Ronnie married Caitlin Snow (Danielle Panabaker), the team stopped Reverse-Flash (Tom Cavanagh) and ripped a whole between worlds and Firestorm helped close it… but it forced the separation of the two with Stein coming through to this world and Robbie now presumed dead.
Because the Firestorm matrix needs it's partner and with Robbie gone, Team Flash spent part of season two searching until they found a second possible partner in Jefferson Jackson (Franz Drameh). And then later in the season, the new Firestorm would become part of the Legends of Tomorrow, becoming series regulars in all three seasons up until this weeks crossover. Word came out in September that Garber would be returning to Broadway as part of a revival of Hello, Dolly!. And in October it was confirmed the Garber would be leaving the series.
The season began with the team being disbanded by the Time Bureau and Stein at home with his wife and daughter (who was created in a time anomaly) and finding out that he was going to be a grandfather. Even though he returned to the Waverider along with Jax when the team reformed, it was obvious where he truly wanted to be. They began working on a way to separate permanently and not have Stein blow-up. Part of this lead to an interesting, Freaky Friday style episode with them taking over each other's bodies and Firestorm looking like Stein for an episode.
One of the early things we learn in Crisis on Earth-X is that Cisco (Carlos Valdes) and Wells (Tom Cavanagh) have created a serum that will fool the matrix into believing the two are connected and allowing Stein to go home and Jax to continue on with the Legends… but no more Firestorm. This leads to an exploration of the father/son relationship that has grown between Stein and Jax. But when they are trapped on Earth-X and are fighting an army of Nazis, Firestorm has to separate so they can open the portal back to Earth-1… and Stein is fatally shot. They reform Firestorm and get through the portal, returning to the Waverider in hopes of saving Stein, but we learn that not only is he too far gone, but the connection between them is keeping Stein alive while its killing Jax. After a tearful goodbye, Stein drinks the serum to save his young partner. Jax takes it upon himself to tell Stein's family and even speaks at the funeral.
Victor Garber has left the series. Martin Stein is dead… but where does that leave Jax and Firestorm?
In the comics, when professor Stein died, Ronnie Raymond merged with a new character named Jason Rusch. Ronnie took the backseat then and Jason was Firestorm. So it is possible in the comics for Firestorm to exist without Stein as long as there is another partner. The could bring Robbie Amell back to the show as they never found Ronnie's body. He did come back to play Deathstorm on the Flash. But he is also tied into the X-Files series now.
In the trailer for next week, we see the team dealing with Vikings and for some reason the younger version of Professor Stein (Graeme McComb) is there. They might try to make that connection work, but that's Stein before the particle accelerator explosion. They could jump to the future and find Stein's new grandson Ronnie and maybe he would be able to merge. Or they could just go with Jax alone for a while. But Firestorm is really the big gun of the team. I can't see them going without the character for too long. Plus, as a writer, the idea of having a new partnership to tell stories about could be too tempting to pass up.
With the midseason finale next week and the show's return date not set yet, it could be a while before we know how they will deal with the departure.
Meanwhile, thank you Mr. Garber for the seasons of entertainment… and 'break a leg' with Hello, Dolly!