Plot summary
Clarke and Jasper regroup with Bellamy, Octavia, Monty, and Sinclair. They decide to carry out Raven's original plan to free herself from A.L.I.E.'s control: by building an electromagnetic pulse device (EMP) from one of The 100's old wristbands and frying the chip inside her. Clarke leads the group to Niylah's trading post, where there is a salvaged bracelet. Monty and Octavia return to the dropship to retrieve additional components for the EMP, but they are attacked by Monty's mother Hannah, now under A.L.I.E.'s control. Monty fatally shoots his mother to save Octavia, and they return to Niylah's, where they are able to destroy the chip inside Raven using the EMP and Clarke cuts out its liquefied remains using Titus' Flamekeeper kit. Raven reveals to the group that the Flame is the only thing that can stop A.L.I.E.
Credits
Adapted from Wikipedia contributors, List of The 100 episodes. HTML formatting and reference markers removed.