The show begins in Arkadia where we see Bellamy and Clarke are busy at work. Clarke and Raven start to talk about how food will be rationed. Raven also smugly reminds Bellamy about what destroying the hydro-generator did. Due to his actions last week, the lack of water will affect their crops as well and their overall chances of survival.
Outside the gates of Arkadia, Floukru Grounders show up with sick people coughing. One of them is Luna and she begs them not to turn her and the sick away. Abigail comes out, investigates and tells Clarke that it's ARS (acute radiation sickness) due to their fever and vomiting. They're informed by the Grounders that even the fish are dying. They decide to take them inside to Alpha Station to investigate further. Clarke then says to Bellamy, "It's already here."
We're taken to Polis after the initial events in Arkadia, where Roan approaches Octavia. He wants her to handle something for him in the same way that she handled Rafel. She says that if he can't trust Indra, then he can't trust her. Therefore, he needs to speak in front of Indra as well. Roan says that the Flame got stolen from his quarters. Octavia wants to search everyone, but Indra says no. If everyone finds out that he lost it, the other clans will question his rule. Octavia says that she'll handle the search effort. Roan says that one kill to preserve thousands is good politics.
The show then takes us to a cave where Murphy and Emori are talking, Murphy says that he misses Polis. She questions him whether he had sex with Ontari or not. It becomes a tense situation, but Murphy smoothly ducks the question. He decides to go to Arkadia to steal something. He kisses her and tells her that they will feast tonight.
Back at Alpha Station, Bellamy sees a bunch of the sick Grounders vomiting black liquid. The radiation is from fish that they ate. Luna asks if she deserves what she has for refusing the flame. Clarke says that they will do everything they can. Outside of the med bay, Bellamy finds Thelonious Jaha getting into a vehicle and tells him to get out. After exchanging some words, Jaha explains that he may know of a place that can hold thousands of people instead of only 100. Raven doesn't trust him, but Clarke tells her that if Jaha is wrong then she will make a list of the 100 that need to survive. The scene ends with Clarke, Jaha, and Bellamy leaving to look for the bunker that was built by a doomsday cult, known as "The Second Dawn."
During their drive in search of the bunker, Jaha shows a video of what Second Dawn is all about. There's a man preaching about it and soliciting donations. Jaha explains a bit more about the funding of Second Dawn and that the donations were used to expand the bunker. Bellamy feels like he is a religious fanatic, but Jaha feels that the details don't matter as they proceed deeper into the woods.
Murphy shows up to Arkadia and runs into David and Nathan. David asks Murphy if he's here to stay and Murphy claims that he's there to stay. He sneaks in and starts to steal some food. However, Abigail approaches Raven to ask for anti-radiation medicine. Unfortunately, Raven declines her request. She asks Abby if she can guarantee that the medicine can save them, but she can't. She says that they have to try, especially since there's a child. Raven says that they can't waste any of their supply. Additionally, they'll be dead in two months even if they can save them today. Abby sharply responds by saying that the radiation isn't killing them, but Raven is. During this exchange, Murphy happens to overhear everything.
In the med bay, Murphy walks up with stolen anti-radiation meds and gives them to Abigail. She instructs Jackson, to give it to the child first. Abby also expresses happiness that John is back since she was worried about him. After the child is given the meds, the plan is to wait a few hours. If it works, they will treat the adults later.
Back in Polis, we see a cloaked female with a box containing the Flame chip. Octavia is onto her trail and is following in pursuit. She finds the thief, and they start to fight in some sort of cave temple. Octavia gets the upper hand in the fight and is set to run a sword through the thief. However, Indra appears and stops her. She also reveals that the thief is her daughter, Gaia.
Indra begins to debate with Gaia because she feels that she was meant to lead people. However, Gaia claims to be the keeper of the flame now and is more concerned about finding Nightbloods. Octavia asks Indra what she wants her to do, and Gaia says that she can run. However, Indra doesn't want her to throw her life away. At this moment, a group of men led by Ilian show up and are breaking into the cave temple. Instead of allowing Gaia to run, Octavia seems to have a different plan in mind.
After Ilian's men break into the temple, he explains that they only want the tech and that no one needs to get hurt. One of his men grabs Gaia's bag that has the Flame and gives it to Ilian.
He proceeds to destroy the Flame saying that it's for his mother. The men then proceed to ransack the cave temple.
After the men leave, Octavia picks up the broken pieces and stashes them away. She also apologizes to Gaia for what happened to her pendant which looked nearly identical to the Flame. It appears that they swapped the Flame with Gaia's pendant and Ilian destroyed the wrong thing.
Octavia tells Indra that Roan won't have her head if he doesn't think it was Gaia that took the Flame. It appears that she has another plan to help out Indra and her daughter.
Back at Alpha Station, we see Luna holding the child with Murphy watching. Raven enters the med bay and pulls some of the stolen food out of his bag. Just as she's ready to reprimand him,
Abigail returns the meds to Raven and says that they only wasted one dose. At that point, Raven watches Luna consoling the child before she dies in her arms.
Back in the woods, we see Clarke, Thelonious and Bellamy still driving and searching. Jaha informs them that the bunker will be at the lowest point. He also tells Bellamy that he keeps Clarke centered and that he made the right choices in the past despite the outcomes. Clarke finds something, and it's a staircase. They go down the stairs and after sifting through some cobwebs, they find skeletons. Bellamy picks up a pendant from one of them and the number 11 is on it in Roman numerals. He then knocks on a door and wants to know if anyone is there. Jaha says that it's still sealed and designed to be opened from the inside. Bellamy decides to tie a rope to the door and use the rover to try and pry it open. He finally breaks a hatch off the door and they go inside. Bellamy lights a flair and they find thousands of skeletons. Sadly, it looks like the bunker won't be their salvation after all.
Back in Polis, Octavia returns to speak with Roan. She opens a sack with the head of a man she beheaded and says that he is the thief. She also hands over the crushed pendant and says that the Flame was destroyed. Roan said that more people will have to die to keep him in power before dismissing her.
After Octavia's meeting with Roan, we see Murphy return to Emori and tell her that they need his people. She said that they should make themselves useful. They head over to Arkadia while John explains what's going on with the radiation and why they need to be at Alpha Station.
Back at Alpha Station, Clarke is working on her list of 100 designated survivors. She writes Bellamy's name as number 99 but is stuck on choosing the 100th person. She starts to cry and then Bellamy walks up to her. He says that if he's on the list, then she's on the list. Bellamy also warns that he'll write her name down if she doesn't. He then takes the list and writes Clarke's name on it as the 100th chosen survivor. After she asks about what they should do next, Bellamy says that they should put it away and hope they never have to use it.
Clarke puts the list away and walks to the med bay. She sees Luna praying around more dead bodies and approaches her. Luna appears to be fine despite not receiving treatment. Abigail wants to run tests on her and Jackson asks what she did. Abby then realizes that Luna is different because of her Nightblood. It's the same blood that also happens to run through Clarke's veins. The show then ends with Clarke saying, "From the ashes, we will rise."
Several names on Clarke's list are of crew members, e.g. Shawna Benson, Nick Bragg, Paxton Downard, Anthony Vani, Brian Lyster, Jenna Gouchey, Darryl Marko, Brian Corkum, Gerri Crawford, Ray Garrioch, Ben Russell, Sara Mineo, Sam Hardie, Darah Wyant, Cory Roberts, Athena Wong, Christine Coutts, Shelby Page, Tia McCurdy, Dustin Allen, Sean Kuzyk, Ron Macleay, Tina Vuu, Doreen Ferreira, Danielle Aufiero, Noah Richoz, Jim Stacey, Quincy Paglaro, Ian Samoil, Arin Ringwald, Ray Garrioch, Chelsea Abe, James Crockett, Alyssa King, Sandra Matossi, Leah Stowe, Susan Crawford, etc.
A few names on Clarke's list are very similar to crew members, e.g. David Halifax, Allisa Swanson, Lisa Warren, etc.
↑Swanson, Allisa (15 Feb 2017) Tweet “Terro, who grabbed Gaia's pack was Part of the Lake Clan, look closely, you can see a repurposed life vest as part of his costume.” - @allisa_s (Allisa Swanson is the costume designer for The 100.)