When The 100 returns, the Sky People will have a new war to fight.

Though they've managed to maintain peace in the three months since the Season 2 finale, the treaty quickly falls apart once a new faction of Ark survivors and the much-discussed Ice Nation are added into the mix. And judging by the first trailer for Season 3, this new war will drastically shift allegiances, even pitting doting siblings Bellamy (Bob Morley) and Octavia (Marie Avgeropoulos) against each other in a bloody hand-to-hand brawl.

Meanwhile, Clarke (Eliza Taylor) is seen returning from her isolation following the Mount Weather genocide, reuniting with both Bellamy and Lexa - though she doesn't seem too pleased with the former, holding her ex-lover at knifepoint.

Check out the epic first trailer for The 100's third season above.

The 100 returns Thursday, January 21 at 9/8c on The CW.

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