Murphy's Law is the fourth episode of the first season of The 100. It is the fourth episode of the series overall.
After the shocking death of one of their own, Clarke tries to make her mother feel what she is feeling. Octavia tries to get Jasper to go outside the wall, which leads them to discover important evidence that could lead the 100 to the killer. Now, Bellamy must try and keep the group from turning on one another as life on Earth takes a devastating turn.
On the Ark, Abby and Raven take dangerous risks to acquire an extremely vital part needed for the pod, but time begins to run out for them when Kane learns of their plan.
At the Camp, all is quiet as Clarke leaves flowers at Wells' grave. Finn approaches and tells her she should not be out all alone because that is how the Grounders got Wells. He then produces a colored pencil and tells her he got it at the Art Supply Store. Clarke begins to reminisce how Wells was always getting her drawing materials by trading in his own stuff on the Ark. She tells Finn how Wells let her hate him so she wouldn't hate her mother for killing her father and decides to make her mother feel what she is feeling.
Up in the Ark, an alarm sounds in Earth Monitoring Station and Abby sees that it is Clarke's title that has gone dark this time. Jackson tries calming Abby as Abby tries to rationalize why Clarke's wristband would be terminated and asks Jackson for a record of Clarke's vital signs.
In the drop ship, Monty tells Clarke that he did it and was able to keep Clarke's wristband fully operational. Now all he needs to do is patch it into the drop ship mainframe and they will be talking to the Ark by nightfall. Outside of the drop ship, the Delinquents are busy constructing a wall and Murphy reports to Bellamy that they'll be finished with the section they're working on by tomorrow. Connor drops a tree trunk and Murphy gets on his case, pointing out Wells Meanwhile, Murphy has given Connor his "water break" by peeing on him. Murphy then orders the rest of the Delinquents back to work.
On the other side of Camp, Octavia is leading Jasper outside the Camp walls for the first time since he was speared the week before. She is suddenly grabbed and pulled behind a tree stump. Jasper runs outside the walls to save her only to discover that it was John Mbege playing a prank. Jasper turns around to go back inside the Camp and trips and falls and discovers Wells' disembodied fingers and a knife on the forest floor.
Up on the Ark, Kane asks Abby if she is heading to Mecha Station and asks why she has been down there nine times in the past week. He invites himself along but Abby tells him he'll have to be inoculated because a mechanic came down with strep and she doesn't want another outbreak. Kane declines and asks her to keep him informed. Abby then leaves to meet with Raven at the escape pod she is refurbishing. Raven tells Abby the delay is because she needs a pressure regulator before they can launch. Abby tells Raven that Clarke's wristband went out and Raven tells her she will get a pressure regulator that day.
Jasper and Octavia show Clarke and Bellamy the knife and fingers. Clarke realizes the knife belongs to a Delinquent and that the Grounders didn't murder Wells; it was one of them. Bellamy tells Clarke she needs to keep this quiet because fear of the Grounders is building the wall that is keeping them safe. Clarke points out the knife belongs to John Murphy and the Delinquents have a right to know that he murdered Wells. Clarke storms out of the tent and confronts Murphy about the knife. She tells Murphy he's going to pay for it and Octavia pipes up that Murphy also tried to kill Jasper. Murphy says he doesn't have to answer to anyone when Bellamy steps in. Murphy tells Bellamy he didn't do it. Clarke asks the crowd if they want a society with no rules. Connor shouts out that they should float Murphy and the crowd agrees. Connor says it is justice but Clarke calls it revenge. Connor then begins a chant to float Murphy and the crowd attacks Murphy and beats him as he is bound and gagged. They string up a noose and wrap it around his neck as Clarke begs them to stop. They pull Murphy up on the rope, hanging him from a branch and Connor gets the crowd to chant for Bellamy to kick the crate out from under Murphy. Clarke pleads with Bellamy, telling him she saw him with Atom and knows he's not a killer. Bellamy shoves her away and kicks the crate out from under Murphy, yelling at Clarke that it is her fault for letting everyone know that the Grounders didn't kill Wells. As Murphy twists and wriggles at the end of the rope, Finn comes running up and tries to put a stop to it but Connor holds him off. Charlotte pushes forward and admits that she was the one who killed Wells. Clarke grabs the ax from Bellamy's waist and cuts the rope holding Murphy as Finn unties him.
Up on the Ark, Raven arrives at the Mess Hall to speak with Nygel, the woman in charge of the black market on board the Ark. She asks for a pressure regulator and Nygel tells Raven that she'll need to sleep with the Chief of Electrical in order to get the part. Raven tells Nygel to float herself and Nygel tells Raven that her mother took that deal many times, causing Raven to fly off the handle and be carried out by Nygel's workers.
Bellamy, Clarke, and Finn are talking with Charlotte inside a tent. Charlotte tells them she was trying to slay her demons. Outside, Murphy is calling for Charlotte and to let him punish her like they wanted to punish Murphy. Bellamy tells Clarke and Finn to stay inside the tent with Charlotte while he goes outside to deal with Murphy. He tells Murphy he was just giving the people what they wanted. Murphy turns to the crowd and asks if they want to see the real murderer hanged. No one in the crowd responds and this angers Murphy since they had no problem watching him get hanged for nothing. Bellamy tells Murphy it is over and heads back toward the tent when Murphy knocks him out from behind. Murphy then punches Jasper and storms the tent, only to find out that Finn and Clarke had already escaped with Charlotte.
Back on the Ark, Raven is waiting in a long line for Medical. She approaches Abby and coughs discreetly and Abby does a cursory medical check on her before pulling her away into private, explaining the long line is due to oxygen deprivation. Raven tells Abby that Nygel would not give her the pressure regulator and Abby tells Raven she can get the part from Nygel. Later, Abby approaches Nygel in the Mess Hall and slips Nygel some morphine for a pressure regulator.
Clarke, Finn, and Charlotte are trekking through the woods when Charlotte reaches for Clarke's hand. Clarke jerks her hand away and calls Charlotte a killer and tells her she can't just kill someone to make herself feel better. They hear Murphy and his followers calling out for Charlotte and Finn gestures to a hatch in the ground, revealing his Art Supply Store, or rather a pre-war bunker that the inhabitants never made it to. They tuck Charlotte into bed and Clarke tells Finn they should share all of the supplies with the group but he thinks they should keep it secret. Clarke thinks the original owners might have been better off dying before making it to the shelter. She tells Finn she doesn't know what to do about Charlotte and that it's all her fault as she should have listened to Bellamy about confronting Murphy. Charlotte listens to their conversation quietly from her bed.
At the refurbished drop ship, Abby hands Raven a pressure regulator and Raven tells her it might take a few hours to install it. Meanwhile, Kane enters the Mess Hall where his mother, Vera Kane is holding a worship service of sorts for the original members of the Ark and the "last tree." Vera pauses, thinking Kane is there to see her, but Nygel tells Vera he is here to see her. Kane asks why Nygel summoned him and Nygel tells him that both Abby and Raven asked for a pressure regulator and provides the morphine as proof. Kane leaves with the morphine.
Clarke awakens in the bunker to discover Charlotte missing and wakes Finn up. Meanwhile, Charlotte is running in the woods when Bellamy grabs her and tells her to keep quiet. Murphy and his lynch mob are also traipsing through the woods searching for her. Charlotte tries to get away from Bellamy and tells him she is not his sister and to stop helping her. Bellamy tells her he won't leave her even as she begs and screams out for Murphy to get her. Clarke and Finn hear Charlotte screaming for Murphy and think that Murphy might have her.
Abby is pacing around while Raven works on the drop ship. Jackson comes in on Abby's telecommunication device and asks if she stole morphine. He tells her that Kane is on his way to arrest both her and Raven. Abby can't believe that Nygel turned her in and asks Raven how much longer. Raven tells her twenty minutes and Abby says that Kane will be there in five. She tells Raven that no matter what, Raven needs to launch the pod, with or without her, and radio back or 300 people will die. Abby asks Raven to tell Clarke she loves her.
Bellamy is carrying Charlotte against her will through the woods when they get stopped by the edge of a cliff. Murphy reaches them and tells Bellamy to give her up. Clarke arrives and tells Murphy it has gone too far. Murphy takes Clarke hostage and Charlotte begs him not to hurt Clarke. Murphy tells Charlotte if she comes with him he will let Clarke go. Bellamy stops Charlotte from going to Murphy and Charlotte says she can't let anyone get hurt anymore because of her before she turns around and jumps off the cliff to Bellamy and Clarke's screams of protest. Bellamy turns and tackles Murphy, punching him over and over in the face until Finn pulls Bellamy off Murphy. Bellamy tells Clarke that Murphy deserves to die. Clarke tells him they don't get to decide that and she was wrong before and they need rules. She tells him they will make the rules and they should banish Murphy. Bellamy picks Murphy up and holds him near the cliff's edge, telling him that if Murphy ever comes back to the Camp, Bellamy will kill him. He then tells Murphy's four followers that they can either go back to camp or they can go with Murphy and die. The four followers head back to camp with Clarke and Bellamy while Finn tosses Murphy a knife before leaving.
Up in the Ark, Raven gets the pressure regulator hooked up as Kane heads toward Mecha Station to arrest Raven and Abby. Raven realizes the pressure regulator is broken just as Kane approaches Abby who was waiting for him in a hallway. Abby tells him she did it for her daughter and she still believes the delinquents are alive. Kane asks Abby what the pressure regulator is for and if there was even a strep infection. Raven dresses in a spacesuit since the pressure in the drop ship won't be regulated and begins the launch sequence for the pod. As Kane is having Abby arrested, Raven launches the drop ship and begins her descent to earth. Abby tells Kane they have to know the truth.
Back at the Camp, Clarke, and Bellamy explain the new rules to the rest of the Delinquents. Later at the drop ship, Monty has the wristbands ready to hook up to the dropship and gives Jasper the honor of making the final connection. As Jasper makes the connection, it fries everyone's wristbands and Jackson in Earth Monitoring Station witnesses all of the remaining wristbands terminating at once. Finn takes off in frustration and Clarke follows after him. Jasper sits down, dejected for frying the wristbands. Octavia joins him and tells him he is not cursed. She calls him brave for standing up to a bully and tells him that bravery is always rewarded before kissing him on the lips.
Clarke catches up with Finn at the bunker where he is throwing things around in anger because he believes everyone is going to die on the Ark, leaving them all alone on Earth. Clarke says he is not alone before the have sex for the first time. Unbeknown to them, Raven continues her descent to Earth, her raven necklace floating weightless in her escape pod.
Clarke: "You know, when we were kids, Wells was always giving me ink, charcoal...just anything I could draw with, really. I found out later that he was trading his own stuff to give it to me. He didn't want me to know that either. He let me hate him so that I wouldn't hate my mother."