Blood is thicker than water, but that won't be enough in the upcoming wars on The 100.

Octavia (Marie Avgeropoulos) and Bellamy (Bob Morley) are once again on opposing sides now that the latter has decided to join up with Pike (Michael Beach) — and Bellamy's decision will put Octavia in a very tricky situation, according to Avgeropoulos.

"She's constantly struggling to do what's best for her people, but she also cares about her brother so much," she says.

Though Octavia ultimately chose loyalty to Bellamy over the Grounders at the end of last season, don't expect the siblingsto be teaming up again any time soon. "In Season 3, she also has a lot of struggles with her brother again," Avgeropoulos teases. "There's going to be a lot of wars and Bellamy and Octavia are on opposing sides."

Are you sad to see Octavia and Bellamy at war?

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

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