Clarke frantically tries to make sense of her surroundings; an enemy returns; Octavia and Lincoln's daring plan turns out unexpectedly; Jaha comes to a decision.
Clarke demands answers from President Dante Wallace; Abby must perform emergency surgery; Octavia is willing to do anything to locate Lincoln.
Clarke joins forces with an unlikely ally after discovering a horrifying project in Mount Weather's medical ward; Kane wants Abby to be brutally punished; Octavia fights for Lincoln.
Clarke tries to prove that she won't go down without a fight; Finn, Bellamy and Murphy race to save a stranger; tension rises between Wick and Raven.
Kane attempts to make peace with the Grounders; Jasper participates in a risky experiment; President Dante Wallace issues a warning; Finn's search for Clarke turns violent.
While tension grows between Finn and Clarke, Raven learns that Mount Weather is interfering with communication systems; Octavia is faced with her worst nightmare; a betrayal looms for President Dante Wallace.
Abby is willing to do anything to protect her people from an attack by the Grounders; Bellamy persuades Clarke to accompany him to the drop ship, where a dangerous secret comes to light; Dr. Tsing oversees a deadly experiment.
Clarke comes back to Camp Jaha with terrible news; Finn is faced with the consequences of his actions; Abby gets ready for a fight -- and gathers information from an unexpected source.
Lexa and Clarke make a deal; Raven is unable to keep her emotions under control; the newly formed alliance is threatened by a bold move; Monty comes up with a risky plan.
A new enemy puts lives in danger; Lincoln and Bellamy decide to break into Mount Weather together; Octavia receives an irresistible offer.
Lincoln and Bellamy's attempt to get into Mount Weather results in brutal consequences; Clarke steps up; Jasper demands answers from President Wallace.
Tension mounts between Abby and Clarke; Murphy and Jaha have an encounter with a mysterious stranger; Octavia is willing to fight for someone important to her.
Clarke questions Lexa's decisions; an injured Kane needs Abby's help; Indra pushes Octavia; Cage puts Maya in jeopardy.
Lexa and Clarke get into a heated discussion during battle preparations; Murphy and Jaha are faced with a perilous roadblock; Bellamy races against time.
Wick and Raven are faced with a setback; Maya and Jasper witness a terrible act; Bellamy makes good on a promise; Cage reveals powerful information.