The show opens up in Becca's lab with Raven asking the main computer for information. Additionally, Jackson finds out the real reason for Nightblood's creation. The reason is to specifically prevent the radiation. Abigail appears to see something different and it doesn't add up to what Jackson sees. Suddenly, Raven begins to have a headache while Jackson and Abigail debate about finding Luna. Jackson insists that she needs more rest and it leads to Abby snapping at him. To her credit, she apologizes to him for the rude response.
Out of nowhere, we see Raven begin to start float as if the room is in zero gravity. However, she suddenly starts convulsing and choking while bleeding from the mouth. Abby injects her with something in order to relax her body and it's clear that something is not right.
Meanwhile, in the forest, as Octavia's horse is taking her home, she falls off. She appears too weak to move on until someone approaches her. It appears to be Ilian, but her vision becomes blurry and goes to black.
Back in Arkadia, we see that it is Ilian, and he brings in Octavia. Niylah calls out for Clarke to help Octavia while Ilian explains that he found her on his way to Polis. Clarke tries CPR on Octavia, but it doesn't seem to work well. However, Octavia eventually regains consciousness and Clarke demands that she gets taken to the med bay. She also thanks Ilian for saving Octavia's life. Before Octavia gets taken away, she starts to mutter that "war is here." This leads to Clarke deciding to walk off and look into what Octavia's grim warning means. We then see Ilian looking around Alpha Station with a suspicious look.
A few minutes later, we see Arkadia's army planning how to defend themselves against this oncoming attack. They know that it's Ice Nation approaching and Clarke decides that she needs to talk to Roan to find out what's going on. She feels that there's some sort of misunderstanding. Some of them disagree, but Monty says that they have the element of surprise. Therefore, it's a good idea and they proceed with the plan.
Afterward, we see Roan and Ice Nation walking toward Arkadia when they see Clarke. He realizes that Arkadia knew they were coming and that they were warned. However, an arrogant Echo claims that there's no way that Octavia survived her blade or the fall off the cliff. Clarke says that she wants to talk and he says it's too late for that. However, Echo informs Roan about a few laser sights on his chest. Arkadia has them surrounded with snipers and it causes him to pause. Echo tells Ice Nation to bring the prisoners and they reveal them to be Bellamy and Kane. Roan then informs Clarke that it's her move now. She asks for 10 minutes to talk and Roan agrees to it. Echo warns that it may be a trap, but Roan responds by saying that they're already in the trap.
Roan walks up to Clarke while Riley is still targeting Roan. His sight is squarely on the head of Roan and he feels they should take him out. He starts to debate with Monty about how he has a clear shot. However, Monty encourages him to stand down before he does something incredibly stupid.
Meanwhile, Echo is getting her archers ready to attack, but Kane tells her that it's insanity. Bellamy then realizes that Arkadia knew that Ice Nation was coming. Therefore, someone clearly warned them and it had to be Octavia. He appears relieved as he realizes that his sister is most likely still alive.
Back at Alpha Station, we see Ilian carrying a wheelbarrow with flammable liquid. However, it's not clear what his plan is. It's obviously nothing good since he's still inside Alpha Station.
Back at Becca's lab, we see Abigail revive Raven and inform her about her seizure. However, Raven doesn't believe her and tries to tell her that she's not crazy. Abby and Raven begin to talk more about the bonding of Nightblood. Abby tells her that it didn't work before due to an issue with the RNA structure. Suddenly, Raven has a revelation about the bonding of Nightblood. She tells the computer to show her the RNA bond of Nightblood in zero gravity. Suddenly, it shows an image that clearly shows the answer for properly creating Nightblood.
Unfortunately, they don't know how to simulate Nightblood and Jackson feels that it's impossible. Raven realizes that it's not possible on Earth, but it is in space. As a matter of fact, she feels that's the reason why Becca truly went into space in the first place. She tells the computer to open interior blast doors and it unveils a room with a space pod and a launch portal above it.
Back at the standoff between Ice Nation and Arkadia, we see Monty has Echo in his sniper sight. Suddenly, they notice that Riley has taken off somewhere and he left his radio where he was posted. Monty realizes that Riley's only goal is to kill King Roan, but he needs to stop it. He leaves his position next to Harper and goes to warn Echo about it.
Seconds later, we see Clarke and Roan in a cave talking. She says that they're allies, but Roan disagrees. He also informs her that he's not going to Arkadia to kill them. What he actually wants is to take Alpha Station. He feels that there's a conspiracy against him, but she tries to convince him that there's not. However, he continuously brings up the Alpha Station situation while she tries to tell him about the Nightblood solution. He then demands that Arkadia gives him Alpha Station while they work on the solution. Clarke reminds him that they have more people and guns. They debate some more, but then Clarke asks what happens if they share Alpha Station. This seems to make Roan reconsider his original plan.
Back at the standoff, Monty wants to speak with Echo and informs her that Riley is trying to kill the king. Echo decides to go off to find him, but that will lead to certain death. Arkadia's snipers have orders to shoot anyone that steps outside of an invisible "kill border." Bellamy suggests that he goes with Echo since he knows Riley and can talk to him. Echo then tells her soldiers to unshackle Bellamy and hold Monty as hostage. She informs them to kill the hostages if they're not back at a certain time.
Back at Becca's lab, Abigail is monitoring Raven's brain usage as she continues to work. She sees a spot in her brain and realizes that it's the sign of a stroke. She begins talking to Raven about an EMP causing damage to her brain. However, she also realizes that some of A.L.I.E.'s code is still in her head. Abigail then informs Raven that her brain activity shows signs of a stroke. She also tells her that if she keeps going full speed, it could cause her death. Raven tells her to let her go since she needs to get to work for the sake of everyone else. Jackson wants to scan Abby's brain as well, but she refuses.
Back in the cave with Clarke and Roan, we see them agree that 50 seats a piece is a good compromise. He asks how she will inform her people, but she claims that she'll figure it out. They then agree to it with a bond in blood.
Echo and Bellamy start getting closer to Riley in the forest. They find him in a prone position with his sniper rifle aimed at the cave opening. Bellamy tries to talk him down while Echo aims an arrow at him. He continues to talk to him as he as his cross-hairs set on Roan leaving the cave, but he doesn't pull the trigger. He puts his gun down and starts to cry.
At Alpha Station, we see Niylah carrying Octavia while looking for Ilian. She knows that Ilian is there to destroy tech and that he's most likely in the server room. We see him in the server room as he's pouring a flammable liquid on the floor. He then says a prayer to his brother and proceeds to put a torch to it. Octavia tells him that they need the ship for survival. He asks her if she was ever in the City of Light and if not, then she'll never understand. He then drops the torch and the server room blows up.
Inside Alpha Station, Ilian decides to save Octavia and Niylah by dragging them both outside. Clarke and crew return to the burning Alpha Station and want to know where Octavia is. They see Ilian walking with her and Niylah out of the station. Bellamy takes his sister and begins to tend to her. Octavia then tells Clarke and Bellamy that Ilian is responsible for the explosion. Suddenly a loud explosion happens and the station begins to collapse. Everyone looks on with somber faces as it seems like all hope is lost.
Back at Becca's lab, we see Abby looking into a microscope, then she thinks she sees Clarke standing at the space pod. The figure then turns around and it's an image of Clarke with a diseased face and she says "You're running out of time, mom."