Without enough fuel to get to space, Clarke (Eliza Taylor) must find a new way to save humanity on The 100 — and it seems her mother might have the answer.

In this exclusive sneak peek at Wednesday's episode, Abby (Paige Turco) reveals that instead of making their own nightblood, they might be able to turn people into Nightbloods by injecting them with Luna's (Nadia Hilker) bone marrow. However, Abby says that she previously decided to take that plan off the table since the only way to make sure it works is to test it — and the only way to test it is to expose someone to "enough radiation that would implode every single cell in their body." Yikes.

But with no other option left, Clarke and Abby realize that they now have to choose whom to use as their test subject. That is, if Emori, who overheard this whole conversation, doesn't find a way to stop them from moving forward with their sacrificial plan.

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

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