SPOILER WARNING: This article contains major spoilers for "Beebo the God of War," the midseason finale of DC's Legends of Tomorrow Season 3.
DC's Legends of Tomorrow may have lost a member, but they didn't go long without filling the gap. In "Beebo the God of War," the midseason finale, Jax made the decision to leave the team, only for John Constantine to step on board.
In the opening of the episode, a young Martin Stein was transported into the past as part of an anachronism. However, he wasn't alone: he brought with him Beebo, a Furby- and Tickle-Me-Elmo-inspired animatronic doll. The Vikings he encountered took Beebo for a god, allowing Martin to be spared but causing a level 12 anachronism.
Seeing young Martin stirred up a lot of feelings for Jax, who still hadn't gotten over older Martin's death from "Crisis on Earth-X." Jax wrestled with his feelings throughout the episode, ultimately giving young Martin a letter that would have shown him how to prevent his death. Martin recognized the move from Back to the Future and quickly burned the letter so that he wouldn't know anything about his future, allowing him to live a normal life. As such, his death in 2017 remained the same.
As the episode drew to a close, Jax realized that being on the Waverider brought up too many memories of Martin for him. He made the decision to step down from the Legends so that he could process Martin's death and come to terms with it. After his team threw him a Christmas-themed goodbye party, they dropped him off in Central City in 2017. It is unclear if and when Jax will return to the show.
However, another Arrowverse character managed to sneak on board during the drop off: Constantine, the same man who restored Sara's soul in Arrow Season 4. When Sara returned to the ship after saying goodbye to Jax, Constantine was already in the cargo hold. He lit up a cigarette and informed her that he had encountered a demon possessing a young girl that knew Sara Lance by name. Now, he will team up with the Legends to learn more about this threat.
Returning in February 2018 on The CW, DC’s Legends of Tomorrow stars Victor Garber as Martin Stein, Arthur Darvill as Rip Hunter, Dominic Purcell as Mick Rory/Heat Wave, Caity Lotz as Sara Lance/White Canary, Franz Drameh as Jefferson “Jax” Jackson/Firestorm, Brandon Routh as Ray Palmer/Atom, Maisie Richardson-Sellers as Amaya Jiwe/Vixen, and Nick Zano as Nate Heywood/Steel.