The 100 fans know well enough to brace themselves when anything good happens, because just after the rise inevitably comes the fall. That's exactly what the CW drama did when — after being separated for the majority of the season — the Blake siblings finally reunited in an emotional moment, only for them to be almost immediately separated again.

At first, it seemed as though the separation would only last a few hours, just long enough for Bellamy (Bob Morley) to help Clarke (Eliza Taylor) & Co. bring Raven (Lindsay Morgan) back from Becca's lab. However, when it quickly became clear that the group would never make it back in time, reality set in that even if Bellamy managed to survive the death wave, he'd be separated from his sister again — only this time, the split would last at least five years.

Creator Jason Rothenberg told that, fans' disappointment aside, this separation was necessary for both Bellamy and Octavia's (Marie Avgeropoulos) growth. "Bellamy and Octavia's journey this season was in large part about, for Bellamy anyway, realizing that his sister was a grown up and essentially, he needed to let her be her own woman instead of trying to always take care of her. I think some of that, by itself, implies separation so that that could happen," Rothenberg explained, before cheekily adding, "Of course, it didn't have to be that way, but I don't know."

Over the course of the series, Bellamy and Octavia have both risen up through the ranks and taken on pivotal roles in grounder politics — roles which have often put them at odds, but pushed them into becoming better people. And now that Octavia is essentially the leader of humanity's surviving population on Earth and Bellamy is ready to step up and help lead the small crew heading to space, the pair will get to spend the next few years truly figuring out their own identity and agenda without the influencing factor of each other.

"I think ultimately, obviously, they will be together again at some point, assuming they both survive between the hiatus of Season 4 into Season 5," Rothenberg teased. Although, even if both Bellamy and Octavia survive Wednesday's season finale, they'll be completely different people by the time they see each other again. "What will it be like when they come back together? Will they be on the same page of things? They'll clearly be overjoyed to see each other, but then it will be about sort of now having to live together again," the showrunner mused.

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But before Octavia can even imagine the possibility of a heartfelt reunion with Bellamy, she'll have to deal with the people she is stuck in the bunker with. And ironically enough, the biggest challenge facing Octavia isn't winning over the grounders, but her own people.

"She was the champion of that conclave, and the grounders respect strength and they respect the charms of that deal. Skaikru, not as much," Rothenberg said. "That will probably be the thorn in her side as a leader. How does she keep these people, who perhaps think they deserve more because they think that they're better than the grounders, in check? That will probably be a big challenge for her, for lack of a better word, reign."

The 100 finale airs Wednesdays at 9/8c on the CW.

(Full disclosure: is owned by CBS, one of the CW's parent companies.)