Up in The Ark, Eric Jackson tells Abigail Griffin that rumors are going around about the Delinquents'dropship launch. He reports that 23 Delinquents' tiles have gone dark with spiking vitals prior. Abby says there is another explanation. Someone announces the Chancellor is on deck and Thelonious Jaha walks in and sees Wells Jaha' dark tile. Marcus Kane tells Jaha that the wristbands are telling them that the Earth is not survivable. Abby asks Jaha to trust her because, for all they know, the kids are fine.
Back at the Delinquents' Camp, Wells is finishing burying the two delinquents who died in the drop ship landing. Atom stops Wells and tells him he will take the clothes of the two kids who died and Wells tells him they will share based on need, just like on the Ark. Bellamy Blake interrupts and reminds Wells they are not on the Ark anymore and that down here, there are no rules. Meanwhile, the other delinquents are running wild and there is general chaos. A girl screams in the distance and Wells and Bellamy, who had entered the scene, head toward the noise. John Murphy is holding a girl over an open flame prior to removing her wristband to make the Ark think they are suffering before dying. Wells shoves Murphy over and they get in a fight with Wells winning the fight. Murphy then pulls a knife and Bellamy tosses a knife down in front of Wells, saying, "fair fight." Wells again wins and holds the knife against Murphy's throat when Clarke arrives and stops the fight. Bellamy rushes over to Octavia when he sees she was injured and asks where the food is and what happened. They tell him about the Grounders and all the delinquents gather around to listen as she explains how the Grounders took Jasper. Clarke then sees Wells' wristband is missing and tells them they are idiots because life support on the Ark is failing and taking off their wristbands is killing everyone on the Ark as well as all the delinquents because they need the people from the Ark to come down and help them. Bellamy counters this by calling the 100 "survivors."
Abby is checking Jaha's injuries and asks for his stance on Kane's Population Reduction Plan. If they don't act to reduce the population on the Ark, everyone will be dead within four months from lack of oxygen. Abby wants to give the delinquents more time, but Jaha is skeptical as to whether the Earth is even safe. Kane enters because Jaha asked to speak with him, as Abby is leaving. Kane informs Jaha that Bellamy Blake was the one who shot him. Jaha confronts him about almost floating Abby and Kane says he was following the law. Jaha tells Kane that being a good leader means knowing when not to follow the law. Kane tells him that he had nothing to do with the attempt on Jaha's life but he's not surprised by it because Jaha is too weak to do what must be done and Kane is not the only one who notices it.
Wells finds Clarke in the drop ship gathering supplies and wants to go with her to find Jasper, but she shoots him down. She tells Monty to stay behind to work on communicating with the Ark. When Finn arrives, she discovers that he is too afraid to go because of what happened to Jasper and calls him a coward and leaves. Wells follows Clarke despite her protests, and a disappointed Monty tells Finn that Jasper looked up to him. Outside the drop ship, Clarke approaches Bellamy, who is tending to Octavia's injury. Octavia tells Clarke she is coming but Clarke tells Octavia her leg will just slow them down. Clarke asks Bellamy to join them because he has a gun. Bellamy tells Murphy to come with him and orders Atom to watch Octavia. Bellamy talks to Murphy about his plan to get Clarke's wristband.
Up in space, Raven Reyes is finishing up a spacewalk to repair part of the outside of the Ark. She comes back in through an airlock and Red and another mechanic help her get out of her spacesuit. She asks them about the drop ship launching and Red tells her that an accident during routine maintenance caused them to eject it. Raven lifts up a necklace with a metal charm in the shape of a raven and puts it on. She asks them to stash her gear because she's on her way to visit her boyfriend in Lockup. Red tells her that Lockup was quarantined for some virus and there is no visitation for two months.
Atom tells the Delinquents to build some walls and warns Octavia to stay away from the boys because Bellamy will hurt them. Octavia tells him to prove that he is not her 's "bitch" before grabbing another boy's hand and leading him up to the third level of the drop ship. Atom stops the guy and pulls him away before telling Octavia the guy was in for murder and he's actually protecting him from her before he closes the hatch on her and locks her in. She yells at him that she was locked up for sixteen years just for being born. Monty then announces his presence to Octavia where he is working on the wristbands.
Jackson informs Abby that Kane is lobbying for votes and she should, too. Raven comes up and asks Abby about the quarantine and how she saw open ducts. Abby explains the virus isn't airborne and Raven confronts her about The Council hiding something.
On Earth, Bellamy tries to get Clarke to take her wristband off, but she is unflinching. Finn arrives just then and suggests splitting up to cover more ground. Bellamy confronts Wells about being in love with Clarke and points out that with Finn around, she won't even see him.
Monty is working on taking off Octavia's wristband so he can try to contact the Ark. He pries off the wristband but it dies. Atom opens up the hatch just then and Monty tells her to go ahead and leave. Octavia tells him that Jasper would understand why he stayed behind. Monty asks how she's not a total basket-case after living under a floor. Atom tells her it's because her brother loves her and that he envies it.
Finn asks Clarke why the Grounders didn't attack until after they crossed the river. Clarke tells him the river is a boundary, meaning Mount Weather is off-limits. They discover a trickling waterfall spilling discover a trickling waterfall spilling into a pond and Clarke is relieved they don't have to worry about fresh water. Finn pulls her into the water and they splash around for a moment and discuss her father before Clarke sees Jasper's blood on some rocks on the other side of the pond and tells Finn they need to get the others.
Up in space, Jackson and Abby are going over the data from the wristbands when Abby catches Raven eavesdropping from the air ducts. Raven tells them the delinquents aren't dying; they're taking off their wristbands because they were told not to.
Octavia is making a weapon when Atom brings her over a cup of water. She then spots a glowing, blue butterfly and follows it into the forest where a whole swarm of them are covering the trees. Atom follows after her and finds her with butterflies all over her. She turns and they kiss. He tells her they have nothing but time before they kiss some more.
Murphy asks if they are going in the right direction and Finn spots some more blood before they hear someone moaning in the distance. They head toward the sounds and they find Jasper strung up to a tree. Clarke hurries up to him but falls into a covered pit with Bellamy grabbing her arm just in time. He seems to contemplate letting her go for a brief moment before they all manage to pull Clarke up. Finn offers to climb up and cut Jasper down.
Abby is speaking with The Council, telling them the kids are taking off their wristbands by choice. They ask how that explains Wells' dark tile and Abby tells them the point is the kids need more time. Kane tells her they don't have time because Engineering needs six months to fix the oxygen problem when they will be out of oxygen in four months. Every day they delay the culling, 10 more people will need to be sacrificed. Today, it's 209 and they need to vote now. The vote is split 3-to-3 with the Chancellor to break the tie. Jaha talks about how they were supposed to be a transitional generation but now they will be the generation who either returns to earth or dies out. He still has hope so he will abstain from voting, ending the vote in a tie to be taken up in ten days. He tells Abby she has ten days to get proof.
Finn and Murphy are cutting Jasper down from the tree when they hear a low growling coming from a black jaguar. Clarke calls for Bellamy to use his gun but when Bellamy reaches for it, he finds Wells has stolen it. Wells uses the gun and fires multiple times at the jaguar, grazing it once. The jaguar pounces toward Bellamy and Wells fires the last bullet, killing the jaguar.
Raven is called into a level of the Ark that is considered off-limits. Abby tells Raven that the Ark is dying and Abby has ten days to prove the earth is survivable before they reduce the population by 320 people. Abby reveals a 130-year-old escape pod and tells Raven to get it ready in nine days. Raven tells her she can do it but she is going with Abby to Earth.
Octavia and Atom are cuddling by the fire when Clarke, Finn, and Wells return with Jasper and Bellamy and Murphy return with the dead jaguar for dinner. Later, while Clarke is tending to Jasper in the drop ship, Finn presents her with a metal two-headed deer trinket.
Up on the Ark, more and more of the delinquents' monitors are going dark.
Down on Earth, the delinquents are removing their wristbands for food. Finn walks up and grabs some jaguar meat with Murphy stopping him and asking if he plays by different rules. Finn tells him he thought there were no rules before walking off. Clarke also grabs some food and walks off. Another delinquent tries to do the same but Bellamy stops him and punches him to keep the rest of the delinquents under control. Later, Bellamy catches Atom kissing Octavia and tells Atom he is on first watch. Bellamy and Murphy then tie Atom up in a tree and leave him overnight for "disobeying" Bellamy. In the trees up above the delinquents, a Grounder watches the Delinquents' Camp silently.
Finn Collins (to the 100): "It turns out, when the last man from the ground died on the Ark, he wasn't the last Grounder."
Clarke (to the 100): "Everything we thought we knew about the ground is wrong."
Clarke (to the 100): "You idiots. Life support on the Ark is failing. That's why they brought us down here. They need to know the ground is survivable again, and we need their help against whoever is out there. If you take off your wristbands, you're not just killing them. You're killing us!"
Bellamy (to Wells): "What's wrong with a little chaos?"
Jaha (to Kane): "You rushed to execute the woman who saved my life and if I were dead, you would be Chancellor now and Abby wouldn't be here to oppose you."
Clarke (to Bellamy): "Because you want them to follow you and right now they're thinking only one of us is scared."
In an interview in February 2016, Jason Rothenberg said the two first episodes (this one and "Pilot") are the worst episodes of the series. The episodes have a more "teen drama" feel, causing many viewers to decide not to watch the show further.