[SPOILERS for those not caught up on Arrow ahead.]
In the 100th episode of Arrow, which took place during the DC-crossover Invasion! event, mind-controlling aliens gave Oliver a glimpse of all that he's lost because of that ill-fated boat trip with his father. The perfect dreamworld included both his parents, alive and well, at his wedding to Laurel.
The follow-up episode, mid-season finale "What We Leave Behind," featured the ongoing assault on Oliver's life by Prometheus. As we see Felicity, Curits, and Diggle get their lives torn apart, it's hard not to agree that hanging out with the Green Arrow is a really dangerous and masochistic thing to do. Even though his friends keep insisting it's Prometheus who's responsible for everything, Oliver can't help feeling immense guilt over the destruction of his team.
Arrow executive producer Greg Berlanti had promised a "shocking end" to the winter finale - and while there were plenty of shocks and horrors in the episode, Oliver seeing Laurel in the final scene was the biggest twist yet. TVLine reports that actor Stephen Amell, in a post-show Facebook live chat, revealed he had a very strong reaction to Black Canary's return:
"This was the first script in a long time where I read what happened in Act V and it legitimately freaked me out. Ultimately where we go in [Episodes] 10, 11, 12, 13, is a very cool development. And it certainly raises the stakes for Mr. Prometheus."
How Laurel will play into Prometheus' vendetta against Oliver definitely adds an intriguing layer to what is already some pretty intense drama. Considering how nearly any scenario is possible in the world of Arrow, Amell immediately addressed the first, most basic question from fans about his ex's appearance:
"Is Laurel really alive? I guess we’ll have to tune in [next episode]. People don’t just come back from the dead. Obviously there will be some sort of vetting process [to determine if it's really her]. We delve into that when we come back in the New Year."
Barring any alternate Earth scenarios, there are two possible time-travel-related reasons for Laurel's return. One is that Barry's Flashpoint timeline gave Laurel a different fate. The other is that her sister Sara finally found a way to take out Damien Darhk in the past, thus granting Laurel a future. Additional theories include a carryover effect from Oliver's alien-induced dream, or a traumatizing hallucination that could be part of Prometheus' larger plans to destroy the Green Arrow.
Some fans had suspected that after the season 1 nostalgia the 100th episode kicked off, that one of those lost characters might rise from the dead. Response will likely be mixed on whether viewers want Laurel back permanently or not. She was often a problematic character, who spent entire seasons in tears over angst with Oliver, her family, and her personal addictions. Hopefully she'll have a more powerful purpose next year, whatever the explanation for her appearance is.
Arrow returns with new episodes on Wednesday, January 25, 2017 at 8pm on The CW.