No nightblood? No problem, as once again the heroes of “The 100” find themselves once again with no more easy options.

In this exclusive clip (above) from Thursday night’s Season 3 finale, Clarke (Eliza Taylor) has figured out a way to activate the flame and the information she and her friends need in order to stop ALIE (Erica Cerra) and save the thousands of chipped and brainwashed population.

The solution: To put it inside Clarke’s body.

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Needless to say, Bellamy (Bob Morley) is less than enthused at the idea, knowing what the flame has done in the past to people who don’t have the inky black blood necessary to receive it. But could a Mount Weather-style transfusion between Clarke and the comatose Ontari (Rhiannon Fish) save her life?

Whatever their next step is, it’s interrupted as Octavia (Marie Avgeropoulos) relays more bad news: ALIE’s brainwashed army is literally climbing the Polis tower in order to charge at the last remaining rebels.

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“The 100” has already been renewed for Season 4. The Season 3 finale airs Thursday at 9 p.m. ET on The CW.