The group faces a threat when they discover a new refugee is a spy working for Sentinel Services; Reed visits his estranged father and learns secrets that could prove useful.

Jaha makes a surprising move. Clarke gets help from an unexpected source. Lincoln seeks revenge.

Wick and Raven are faced with a setback. Maya and Jasper witness a terrible act.

Clarke is faced with a difficult choice and Raven helps Bellamy navigate Mount Weather as Dr. Tsing begins to harvest the 47, while Jaha and Murphy encounter a stranger on…

Lincoln and Bellamy’s efforts to get into Mount Weather has some brutal consequences.

Bellamy is able to get Clarke to agree to accompany him to the drop ship. Dr. Tsing is in charge of a deadly experiment.

Tensions are running high between Clarke and Finn. Raven finds out that Mount Weather is interfering with their communication systems.

Kane takes part in a mission to make peace with the Grounders. Jasper decides to take part in a risky experiment. Lincoln enters a world of pain and President Dante…

Clarke wants answers from the President. Abby performs emergency surgery. Octavia will do anything to find Lincoln.

Clarke is still on her own in the white room, frantically attempting to make sense of her bizarre surroundings. Lincoln and Octavia’s plan is ruined and an enemy returns.