The 100 Season 4 Finale

The 100 Boss Previews the Race to Space, a Big Bellamy/Octavia Moment and More in the Season 4 Finale

The clock has been ticking all season on The 100, and before Wednesday’s finale (The CW, 9/8c) comes to a close, it will have finally stopped.

“I knew right away that this is where it was going,” executive producer Jason Rothenberg tells TVLine. “It was about removing every other obstacle, every other choice, in [the characters’] path and presenting this almost suicidal, crazy attempt to go to space to get above the [death wave]. I love sci-fi, and this show really does live in a sci-fi world, so I wanted to find a way to reincorporate space into the story — at least for a little while. And now, going back to space is their only option.”

In the midst of the chaos is an action sequence Rothenberg is particularly — and rightfully — proud of. Let’s just say it involves… someone… climbing… something.

“It took a couple of days to shoot that,” he says of the scene (that I’ve promised not to totally spoil). “Our visual effects team really outdid themselves. I finally watched it myself with the full effects a few days ago and believed almost every moment. … Plus, it miraculously snowed and stuck for a couple of weeks, which added a cool nuclear winter vibe to the whole episode. That was really lucky.”

But the episode isn’t all doom and gloom. The hectic hour begins with a beautiful moment between the Blake siblings, something fans have been waiting for all season — perhaps longer.

“This season, in many ways, was about Bellamy being able to let go and recognize that his sister is her own woman and that she doesn’t necessarily need him to be his sister’s keeper anymore,” Rothenberg explains. “For Octavia to realize how much she does love him is really cool, as these are now two people who are almost talking to each other for the first time as equals. It’s an important jumping-off point for the episode.”

Your hopes for the Season 4 finale? Drop ’em in a comment below.