The show begins with a shot of the different clans running around in chaos. A young boy, Ethan, is looking around for his dad, Hardy, but can't find him. Moments later, we see John Murphy running around asking about Emori. He asks Niylah, but she hasn't seen her. He eventually finds Emori. She tells him that there are only 100 beds for Arkadians in the Second Dawn bunker. Ethan eventually finds his father, Hardy, as well. Afterward, an angry mob of people crowd into the bunker. At this moment, we see Thelonious Jaha talking to Bellamy and Clarke in despair. Tensions are clearly going beyond the boiling point.
Moments later, we see Raven talking to Abby over the radio. She tells Abby that her brain is healing and that she's not having any more seizures. Suddenly Kane asks what Raven is talking about, but Abby doesn't tell him. Instead, she tells Raven that they can talk about that specific topic later.
Later on, Skaikru meets in a room to discuss how many of their people will need to die to accommodate the bunker living stipulations. They realize that over 350 people will need to die and it doesn't sit well with anyone. Kane suggests that they conduct a lottery, but Jaha disagrees. Bellamy then chimes in and says that he wants to get Raven. Clarke agrees with him and insists on joining him. Kane accepts their wish and says that there will be a place for them when they get back.
Seconds later, we see Abby telling Clarke that there's not much room for error. Clarke tries convincing her that everything will be okay despite Abby's grim vision from a few episodes ago. They continue to share loving sentiments, then embrace in a hug. Abby then looks at Bellamy and says to take care of each other. Suddenly, Murphy and Emori bust into the room asking to join. Abigail agrees and tells Murphy that there will be a spot for him in the lottery. He then asks about Emori and Abby says that she'll do her best. Her answer is not a very convincing one.
As they embark on their journey, Bellamy gets suspicious of John's intentions and questions him. Murphy blames their pending doom on Bellamy because of his opening of the bunker's door. He tells Bellamy that there won't be a seat for him or Emori. Then, while the group heads for the truck, Echo sees them and decides to follow them.
Back at Polis, we see Kane telling the Arkadians about a lottery to determine who will survive. However, Hardy questions Kane about who will be running the bunker. He brings up the fact that they know how to operate the machinery and that the Grounders bring no benefit to the bunker. However, Jaha is able to settle him down for a brief moment.
Suddenly, a couple of Arkadians decide to grab Niylah and remove her because she is a Grounder. Octavia puts an end to it. Jaha then asks her what she's doing and that she's one of Skaikru. Octavia quickly reminds Jaha that he's responsible for her mother's death. Therefore, she has no allegiance to him or Skaikru. She then tells Skaikru to hurry up and choose who will be their survivors or they will all die. Afterwards, we see her run into another room after looking at Indra, then walking off.
Moments later, she approaches Niylah and asks if she's okay. Niylah says that everyone is afraid. However, Indra interrupts them and says that this can't go on for long. She then starts talking about some cryptic act that Octavia must go through with if Skaikru can't decide. Octavia then tells her that she doesn't know what to do. Indra tells her that no leader ever does and walks out of the room.
Murphy and Emori are riding on the journey to rescue Raven. Emori laments over having lost their spot in the bunker saying she'd never felt like she'd had a home before that moment. Murphy then reassures her that her home is with him. Bellamy and Clarke are also having a conversation. Clarke tells Bellamy that she didn't mean to hurt him and Bellamy accepts her apology with a smile. Suddenly, a figure jumps out into the road and Bellamy hits him, crashing the truck into a tree as a result. Grounders then ambush their convoy wanting their radiation suits and protective helmets. Just as things appear dire, we see Echo riding on a horse and put arrows through some of the attackers. She then kills more of them with a sword. Clarke and Bellamy finish off the rest.
After the scuffle with the Grounder attackers, Bellamy asks why Echo is there. Echo tells him that she knows about the bunker that's accessible from Becca's lab. She also brings up the fact that she just saved their lives. Therefore, she's hoping for them to do the same.
Back at Polis, we see Kane, Abby, and Nate finalizing the lottery. Then after Nate leaves, David Miller walks in moments later and tells Kane that he's giving his spot to Nate. His reason is that he wants to give his son the best chance to live. Afterwards, Kane and Abby talk after she claims that everything is her fault. Kane does his best to reassure her, however, Abby doesn't feel she is worthy of surviving inside the bunker and instead tells Kane to only pull 81 names from the lottery. Kane is against this and tries to convince Abby otherwise and despite the fact that Abby tells him she loves him, she insists she has made her decision.
Elsewhere inside the Second Dawn bunker, Hardy asks Jaha if he will take care of his son, Ethan if his name isn't drawn. Jaha then says that everything isn't right and that everyone should be able to fight for their lives. He then tells Hardy that he needs them to get the Grounders to open the bunker door again. When that happens, he will handle the rest.
Back where Clarke and Bellamy are, we see Bellamy trying to contact Monty. He gets in contact with him and asks for him to help them get to Becca's lab. Monty obviously obliges and Harper tells him that they should save their friends. Suddenly, Emori begins to cough up blood, and it's clear that she's suffering from radiation exposure. It appears that there's an issue with her suit, and Murphy intends to save her. He demands that Echo removes her suit, but that attempt fails. Suddenly, Clarke takes off her suit claiming that she has Nightblood. However, it's untested Nightblood and could prove to be a dangerous decision. However, they proceed with saving Emori by replacing her suit and helmet with Clarke's.
Back at Becca's lab, we see Raven patiently waiting for everyone to survive. Seconds later, we cut back to Bellamy and Clarke talking about the need to get everyone to Polis. Monty and Harper show up and they start loading everyone into his rover. Suddenly, Clarke begins coughing up a little blood. However, Monty insists that she wears the suit that he had for Jasper. Clarke then tells everyone that Nightblood doesn't work, but there may be another way to save humanity.
Meanwhile, in the Second Dawn Bunker, we see the lottery taking place. Kane calls a few names including Nate Miller's. Moments later, we see Jaha motion to Kane and he tells Jackson to take over the lottery. Suddenly, Hardy interrupts the lottery. He tells everyone to follow his lead once the bunker door is open. He also asks everyone if they prefer a lottery or a fight. Based on the response from the crowd, everyone is perfectly okay with fighting for their lives as they begin chanting the word "fight."
Kane and Jaha are in a separate room Jaha is collecting canisters of gas in order to use it on the Grounders. Kane thinks he's crazy, but Jaha feels that it's the only way. Indra approaches Octavia informing her about the discovery of a Skaikru armory. She asks Octavia to give the order, and Octavia says to pass out the guns to the Grounders.
Back with Kane and Jaha, Kane attempts to stop Jaha, but he refuses. He says that the time for diplomacy is over. Kane continues to try and convince Jaha not to go through with his plan. Meanwhile, Grounders are approaching the area holding the Arkadians. Octavia and Indra approach the door and Indra offers to help Octavia, however, Octavia insists it is her responsibility and the door is opened.
The Grounders and Octavia enter to find the room full of bodies with Kane and Jaha are standing in a corner wearing gas masks. Kane and Jaha decided that using the gas on their own people is the best option for survival. Jaha then says that he knows where Clarke's original 100 list was and that he will find it.
The Grounders are then seen removing the unconscious bodies of over 300 Arkadians with Kane and Jaha instructing them based on Clarke's list. At the end of this sequence, Hardy is removed from the bunker and Jaha picks up an unconscious Ethan to carry him off to safety.
Back at Becca's lab, Raven is staring at a screen. Bellamy, Clarke, Murphy, Emori, Monty, Harper and Echo then arrive. They then mention that they need to go out to space and live on the Go-Sci Ring. Therefore, they ask if Raven can get them into space before the death wave hits. She stares at the spaceship and says that the death wave can kiss her ass. Clarke then concludes the scene by saying that they're going back to the Ark.