Three months after the bunker doors shut, leaving thousands outside to be turned to dust, the survivors are coming to terms with the new situation thrust upon them. Octavia, the new commander, must keep the peace between the twelve clans, uphold law and order, deliver justice and retain hope that Bellamy is still alive. Niylah acts as a trusted friend to Octavia, her advisor and bodyguard, as Indra must not mix political and personal business. As her new second, Niylah supports her new Heda, despite calls that her 'traitorous head' should be removed by grounders and Skaikru alike. Now, tensions rise after supplies from the limited resources go missing, testing Octavia's leadership and character, leading her to ask Niylah to go undercover and find the thief or thieves. Sacrifices must be made to uncover the truth and bring those to justice.