The Dark Year is the eleventh episode of the fifth season of The 100. It is the sixty-ninth episode of the series overall.
TRIALS AND TRIBULATIONS — As Clarke races to save Abby, she learns more about the trials and tribulations Wonkru faced in the bunker, and the impossible decisions they were forced to make in the dark year.
After finding Abby unconscious, Clarke and Madi start working to resuscitate her. Clarke makes her throw up to reduce the opiate intoxication, thereby causing her to regain consciousness. Just then, McCreary enters the room and wonders how Clarke and Madi got in without being detected by "the eye." Without hesitation, Clarke reveals that Wonkru worked with Raven and Echo to turn off the satellite camera and replace its feed with a video loop. Clarke and McCreary make a deal for him to let her and Madi stay as long as Clarke gets Abby back on her feet to treat McCreary and his people.
Madi confronts Clarke for betraying Octavia and Wonkru to McCreary but Clarke insists that it is the only way to keep her and Madi alive. Madi disagrees, arguing that they wouldn't be able to live with themselves. After waking up and hearing Clarke's plan, Abby opposes it too. She tells Clarke that McCreary is a horrible, dangerous person. But Clarke insists that she and McCreary have to work together because they both want the same thing - to stop Octavia. As Clarke works on opiates detox process for Abby, Abby says that she's not worth saving. She starts telling them what really happened at the bunker during the dark year.
It was after being down in the bunker for two years that Wonkru ran out of protein supply (soy beans) due to a fungus infection in the hydrofarm. During a meeting with Octavia, Indra, Kane and Abby, Kara Cooper informed them that the fungus was spreading to more crops. She said that the she had managed to save a few healthy seeds but it would take at least a year to eradicate the infected crops and plant the new seeds to produce proteins. Abby advised that a year without a protein source would do a lot of damage to their health. She told them that there was only one answer - resort to cannibalism. She suggested that the only way they could survive is if they started eating the people who died in the pit. Octavia didn't like the idea but Abby insisted that it was the only way. So, Octavia gave in to save her people from starving.
Octavia then explained the food situation to Wonkru. She told them that while they may think it's a sin to eat human flesh, the biggest sin would be letting themselves starve to death when they know that they're all that's left of the human race. Indra added that those who fought in the arena died so that the rest can live. Their sacrifice should not go to waste. To lead by example, Octavia painfully took the first bite and urged the others to do as well. Some accepted while others including Kane, refused to eat human flesh. However, the only way for this to work is if everyone participated. So, Abby advised Octavia that she should make it a crime for people not eat. And that means, killing anyone who refuses to eat. Octavia hated the plan but Abby pushed her to do it.
Following Abby's advice, Octavia came in for the next meal with a gun and went around the room forcing people to eat. She started persuading them to eat because she didn't want to kill them. However, with no choice, she was forced to starting shooting them on the spot. This got Kane to stop the rebellion and start eating human flesh as well. Octavia hated that she had to do this and carry all the burden by herself. This is what turned Octavia into the dark, Blodreina.
After revealing this to Clarke and Madi, Abby starts crying, admitting that it was her fault. She feels responsible for what Octavia has become. This gives Madi confidence to try and end the war by killing McCreary. Clarke stops her. Madi and Clarke argue and Madi still defends Octavia’s actions. She tells Clarke that Octavia did what she had to do to save her people. Octavia bore the burden so that her people didn't have to - just like Clarke did at Mount Weather. Clarke is shocked that Madi knows about Mount Weather. Madi then calls out Clarke for lying about Bellamy, Raven, Octavia and even Murphy for always being the heroes in the stories when all along it was Clarke who was the hero, until now. Madi says she’s ashamed of her because of what she’s doing now, not fighting. Clarke explains that she did those things in the past to pretect her people but now that Madi is part of her people she will do anything to protect her (even helping to heal McCreary.) Clarke expresses that she never called herself a hero to Madi because she isn’t one and then walks away to go back to helping Abby treat McCreary and his people.
Meanwhile, Raven, John, Emori and Echo are hiding in a cave with Shaw, Diyoza and Kane. They notice that McCreary has called off his people from hunting them and is moving them to strategic positions. They realize that McCreary knows Wonkru is coming. They figure out that Clarke must have betrayed them to McCreary. So, they radio Bellamy to warn Wonkru that all the entrances into the valley are now blocked. However, Bellamy says they don't have a choice because they are already on their way and don't have enough food rations left to return to Polis. So, Echo promises to think of a way for them to get in. Indra and Bellamy tell Octavia about the situation. Bellamy angrily blames Octavia for leading them to a death trap after burning down the hydrofarm back in Polis.
To figure out a way for Wonkru to enter safely, Spacekru leaves the cave and starts scanning the area. Raven urges Shaw to remain behind so that he doesn't get captured and tortured by McCreary to launch the missiles. After noticing McCreary's ammunitions, Murphy suggests stealing it, leaving McCreary without weapons. Unfortunately, they're confronted by McCreary's people with more deadly weapons. Just before Spacekru surrenders, Shaw shows up and gives himself up. He tells McCreary's people that they would probably get a big reward if they take him because he's more valuable to McCreary than Spacekru. They are convinced and let down their guard. Shaw grabs the opportunity to attack them, knocking them down within seconds. Spacekru then jumps in to help Shaw in the fight. After that, Echo is impressed by Shaw's combat skills. But Raven seems disappointed. Later in the cave, Raven reveals that she was only mad because Shaw risked his life and made her worry about him. They share a passionate kiss.
As Spacekru explains what they observed, Diyoza figures out that McCreary is using the battle plan she wrote. She tells them that it was very thorough and no loopholes. However, she says that she has a plan. So, Echo calls Bellamy and Indra to tell them about the plan. Before telling Octavia Echo's plan, Bellamy makes Octavia promise that she would be willing to share the valley with the prisoners if they surrendered. Otherwise, there would be a lot of body count on both sides. Octavia says that she wants the same thing too. She just wishes it was possible without a war. As they get closer to the valley, Wonkru sets up tents for most of the people to stay there while just a few march into the valley. Bellamy says goodbye to Monty and marches to the valley with Octavia, Indra and a couple other warriors.
Just before Wonkru's arrival, Diyoza and Kane surrender themselves to McCreary. However, McCreary doesn't trust them. Diyoza tells him that she knows he's using her battle plan and they've used a loophole in it to tell Wonkru how to get inside the valley. She offers to help him stop Wonkru if he lets her and Kane back in. Kane justifies his position by saying that he would never let the devil (Octavia) inside that valley.