Plot

97 years after a nuclear war, human kind is living in space. 100 juvenile delinquents are sent down to Earth to see if the planet is habitable.

Prisoners are sent down to Earth 97 years after humans had left the planet after a nuclear fall-out. They're sent from a space station where humans now live, but they do not have resources and supplies to live and survive in space station much longer. The 100 are therefore used in order to determine if Earth is habitable once more, the 100 must learn to adapt to their new surroundings quickly but factions begin to emerge amongst the 100 and not everyone is playing ball.—Andrew Skinner

Ninety-seven years after a nuclear apocalypse, people are living in a space station where there are strict rules, enforced by the counselor. Every crime is punishable by death - however underage delinquents are being kept in cells until they're 18. Clarke Griffin (Eliza Taylor) is one of them. She joins a group of 100 underage prisoners that are sent down to earth to test whether it possible to live there again. During the landing, something goes wrong and the communication with the space station is broken. The kids are on their own and quickly realize that not all of them want have the same goals for this experiment. Clarke and some new found friends go on a journey to a nearby mountain where they are supposed to find food and supplies from a shelter. They soon find out that not everything on earth has died during the nuclear war.—Melanie.

Clarke (Eliza Taylor) is sketching on the floor, imagining what its like to be on Earth with the sun on her face, trees around her, scent of wildflowers however she is stranded in space. 97 years have passed since a nuclear apocalypse left the planet contaminated by radiation. There were survivors. Twelve nations had operational space stations in orbit at the time but now they are clustered into one, called The Ark. It is believed that Earth will not become survivable for another 100 years, and then they can go back to it

Guards enter the room 17 year-old Clarke is in a prison cell. They stand her up and put a locking wristband on her wrist. Every crime on The Ark is punishable by death, unless you are under 18, where you just get locked up until, at 18, you are reviewed. As a guard tries to take her father's watch, Clarke struggles and runs outside her cell. She looks out at tiers and tiers of cells. As the guards approach Clarke, a woman comes by and tells them to stop. Its Clarke's mom (Paige Turco). Clarke fears she is going to be executed to preserve resources for the remaining citizens. Her mom tells her that is not true, and instead, she, and the other youthful prisoners, The 100, are being sent to the ground. A guard shoots a tranquillizer dart at Clarke and she falls unconscious.

A pod is launched from The Ark. Clarke wakes, strapped in like the other members of The 100, some sitting, some upright. She is surprised to see Wells (Eli Goree) sitting next to her. He explains that when he found out they were going to the ground, he got himself arrested. There is turbulence Wells says its the atmosphere. A video comes on with the Chancellor (Isaiah Washington) explaining that The 100 have been given a second chance, but that the second chance is also for those left on The Ark. He tells them their slates have been wiped clean.

On The Ark, the citizens demand to know what the pod was. Some yell that The 100 are just kids. Cece (Kelly Hu), speaking for the Council, will not confirm or deny anything.

On the pod, the Chancellor on the video explains that they are being deposited near Mount Weather, a military storage facility, built during the war, that is stocked with supplies to last 300 people up to 2 years.

A boy (Finn) has un-strapped himself from his position and is doing low-g acrobatics to the amusement of the others . . . except Clarke and Wells. The boy stops in front of Wells and says, Check it out. Your dad floated me after all. Wells is not amused. Two other boys have unstrapped themselves as well, and Clarke urges them to re-attach themselves. The pod's drag parachutes deploy and the pod's passengers are tossed about, especially those who aren't strapped in. They are thrown violently against the bulkheads, dismantling cables and conduit, resulting in blasts of steam and showers of sparks.

On The Ark, it's reported that the pod is off-course and in system failure. They have lost all means of communication except for the telemetry from the passengers wrist-bands. The 100 are on their own.

As it appears dire on the pod, Wells tells Clarke he has to tell her something. She says if it's about her father, that she won't listen to whatever he has to say.

The descent rockets kick in and the pod lands softly. One boy (Jasper) notices there are no machine noises, a first for all of them. The 100 unstrap themselves and move about. Finn (Thomas McDonell) is kneeling over one of the boys who had unstrapped himself. Clarke, kneeling next to another body, asks if the boy is still breathing and Finn shakes his head.

The 100 rush to the lower level where the main hatch is located. Clarke rushes down and urges them to stop the air outside may be toxic. An older boy (Bellamy) by the door reasons that if the air is toxic, they will soon be dead anyway. A girl climbing down the ladder sees the older boy and calls his name. She runs over and they hug. She asks, and he explains, he put on a guards uniform so he could get on the pod. They reveal they are brother and sister. Someone calls out that no one on The Ark has a sibling. Someone else calls out that the girl (Octavia) was the one they found hiding underneath the floorboards in one of the resident quarters. Octavia (Marie Avgeropoulos) runs to attack but Bellamy (Bob Morley) stops her. Instead, he lifts a latch and the hatch opens with a blast of steam. Everyone blinks from the bright sunlight, filtering through tall trees. Octavia takes a deep breath of the fresh air and steps out.

Everyone rushes out, including Clarke, who, studying a map of the terrain, determines that they landed far from Mount Weather. She looks up and sees the mountain on the near horizon. Finn comes up behind her, joking that they didn't die in a fiery explosion. She reminds him of the two dead boys who had followed Finn out of his seat. She then points out Mount Weather to Finn. She says its a long, radiation-soaked forest between them and their next meal.

In the control room on The Ark, an older well-coiffed man (Kane), Clarke's mom (Abby), and some scientists (including Jackson) are disappointed that they have lost contact with the pod because now, they cannot determine the conditions on Earth. However, individual screens on the wall of control room tell them the condition of The 100 based on the telemetry from the wristbands and they can use that information instead. They know two of The 100 have perished but reason that it was due to the violent landing. Kane (Henry Ian Cusick) notices that some of the telemetry screens are highlighted in red, indicating spiking vital signs. Abby thinks they may be injured from the landing, or are just excited to be on Earth.

Wells has taken a walk around the pod and tells Clarke they have problems : that they have no communication, and that heat shields on the top of the pod failed and the radio wires are fried. Clarke points to the map and shows him how far they are from Mount Weather. Jasper (Devon Bostic) looks over their shoulders and Wells grabs his arm and pushes him away. A humorless boy (Murphy) backed by a gang of thugs, comes up and tells Wells to back off. Wells tells them they have to figure out where they are. Bellamy, standing with Octavia, tells Wells all they need to know is that they are on the ground. Wells reminds them of the video they saw with the Chancellor, his father, urging them to get to the shelter and supplies at Mount Weather. Octavia says that Wells is not in charge and that they do not have to listen to what the Chancellor says. Clarke says they don't have to listen to what she or Wells or the Chancellor have to say, but they have to reach the food or it will become difficult for them very soon. They have to leave now to traverse the twenty miles before it gets dark. Bellamy suggests that Clarke and Wells, the privileged, go to Mount Weather and bring them back the supplies. Wells tells them they don't understand, that they ALL have to go, but Murphy (Richard Harmon) approaches him and kicks his feet out from under him. Wells slowly gets up and the two face each other, but Finn jumps in between the two, reminds Murphy that Wells has only one leg and that Murphy should wait until its a fair fight. Octavia steps in and flirts with Finn, and Murphy leads his gang away. Bellamy glares at Octavia and reminds her that Finn is a criminal. Octavia, in turn, reminds Bellamy that they are ALL criminals. He takes her aside and reminds her that he came down here to protect her. She says she does not need protection, and having been locked up for most of her life, she cant keep following orders and needs to be free. He whispers that he cannot stay with the group that he did something on The Ark in order to get on the pod, and they will kill him for it if and when the rest come down.

Finn asks Clarke and Wells when they are leaving for Mount Weather. Clarke says right away but Wells wonders how just the two of them can bring enough food for The 100. Finn turns around and recruits Jasper and Monty (Christopher Larkin). Octavia comes by and says shes joining them. Clarke notices Finns wristband is scratched up and he admits he tried to remove it. She says if he took it off, they will think he is dead. Finn says he doesn't care. Clarke asks him if he wants his loved ones on The Ark to think he is dead, or if he wants them to think the Earth is inhospitable and not come down. Bellamy looks on.

The group heads out. Clarke lags behind and tells Wells he should not have come down. When she catches up, Octavia tells Clarke that Finn belongs to her; Clarke says she doesn't care.

In the control room, Cece checks up on Abby. Abby is optimistic as Clarkes telemetry signs are good. Abby gets a call and she tells Jackson (Sachin Sahel) to bring blood plasma. Cece calls to Abby as she is running out and Abby explains that the Chancellor has been shot. Kane looks on.

The group walks on, gaping at the flora. As Finn picks a flower and puts it behind Octavias ear, Jasper is impressed that Finn has game. Monty is unimpressed saying that the flower is poison sumac (Octavia freaks and brushes it off her head), not actually poison but has medicinal purposes his parents are in charge of the pharmaceuticals on The Ark. Clarke urges them along and Finn wonders how she can block the beautiful scenery out. Clarke wonders why they haven't seen any animals and that maybe they have already been exposed to a lot of radiation.

As they continue, Finn asks the boys why they were imprisoned. Monty points out that sumac is not the only herb in The Ark garden. Jasper adds that Monty also forgot to replenish what they had taken from the garden. Jasper asks Octavia what she was busted for and she mumbles, for being born, and runs off to catch up with Clarke. They come upon a six-pointed deer and crouch down in awe to watch it feed. Finn steps on a twig and the animal turns to look at them it has one and a half faces on its deformed head.

The Chancellor is waking up on the operating table, mid-surgery, and Abby insists they increase his anesthesia. Jackson reminds her that they have already used the patient allotment of anesthesia and blood, so she goes to increase the dosage herself. Outside, Shumway (Terry Chen) reports to Kane that they've determined that the shooter was Bellamy Blake, a janitor. He has a sister who their mother kept hidden from them for sixteen years. Shumway reminds Kane that he, as Chancellor pro tempore, can start reducing The Ark population by the proposed 300 citizens immediately. Kane says, not yet, but Shumway reminds him that the removal of The 100 only bought them a months time, and that is not enough time for the engineers to find a way to extend their existence on The Ark, if they even can. Kane tells him to back off. In the meantime, Kane wants to know who helped Bellamy get on the pod surely there is another traitor around.

At the camp, Wells is gathering firewood. He sees that etched on the side of the pod is First Son, First to Dye. Murphy and a henchman come by. Clutching a knife, Murphy tells Wells that his father begged for mercy in the airlock chamber before Wells father floated him. Wells bumps him as he walks off, telling Murphy that he spelled Die wrong.

Bellamy has been watching this and sarcastically advises Murphy not to announce the fact that he plans to kill someone before he kills him. Bellamy tells them that they need to stop the authorities from coming down, that they would never forgive their crimes, and even if they do, they will always be second-class citizens. He recommends they remove their wristbands that The Ark will think them dead and that it is not safe to come down. Bellamy tells Murphy that the additional benefit is that he will make him his enforcer.

Abby returns to the control room and finds out Murphy and his henchmen have died. Kane thinks its from the radiation, but Abby says they wouldn't have died so quickly.

As the group continues, Finn wonders why the Council chose today to send them to ground. Octavia doesn't care, shes enjoying her freedom. Clarke says its because The Ark is dying that there is only three months left of life support, maybe four, now that The 100 has been sent down. Finn realizes that this information is why Clarke was imprisoned and her father, an engineer, was floated. Her father thought the citizens had the right to know but that the Council, and her mother, thought it would cause a panic. Monty hypothesizes that they will have to kill more citizens. Finn says they have to warn the citizens. Clarke looks at him and says that is what her father said.

Octavia has run off ahead, stands on top of a rock formation, and is taking off her clothes,. Down to her underwear, she jumps off. They catch up and see that she is shoulder-deep in a large river. Monty reminds her they cant swim, but she stands up, now waist-deep, and says they can stand. Clarke is alternately happy and confused there is not supposed to be a river there. Finn says that doesn't matter and tells her to take off her clothes. As Jasper undresses, he sees in the distance a disturbance in the water, and it is coming closer to where Octavia is wading. Despite his warnings, a large sea snake grabs her and drags her under water and disappears.

They look out over the river but only see calm waters. Suddenly Octavia pops up on their far right, still being dragged by the sea snake. Finn makes to get in, but Clarke holds him back and gets him to help her push a large rock into the water. It falls in, makes a large splash, and the sea snake lets go of Octavia and heads towards the distraction. Jasper dives in near Octavia. The sea snake comes back towards them but Jasper drags her on to the shore just in time. Octavia has a large bloody wound on her thigh but manages to hug Jasper. Clarke tears a strip from Jaspers shirt and makes a tourniquet. Monty pats Jasper on the shoulder and tells himself that next time, he will save the girl.

Wells hobbles out of the pod and hears primal yelling and screaming. The 100 are gathered around a bonfire, making a ceremony out of removing the wristbands. He confronts Bellamy, reminding the crowd that The Ark will think them dead and not follow down. Bellamy mockingly calls him Chancellor and says that is the point, and that they can take care of themselves. Wells says the people up there are not just their family and friends but their farmers and doctors and engineers as well. Wells asks if it is safe on Earth, how they can NOT want their people to come down. Bellamy says that HIS people are already there. And that the people up there locked HIS people up, and killed his mother for the crime of having a second child, which he blames on Wells father. Wells says his father didn't write the law, to which Bellamy retorts that here, there are no laws; and that here, they can do whatever the hell they want, which begins a chant among The 100. A thunderstorm breaks and Wells tells Bellamy they need to collect the rainwater. As The 100 dance in celebration, Bellamy replies, whatever the hell Wells wants.

In the control room, they see more of The 100 dying, however, Jackson also notices that plasma osmolality is going up, so they must have found water. Kane comes in with security and they arrest Abby for over-using the allotment of anesthesia and blood on the Chancellor. She says she broke the law and used whatever it took to keep the Chancellor alive, to keep Kane from becoming Chancellor. He takes this as a confession and says he has no choice but to find her guilty. She counters that there is always a choice like when Kane chose to press charges against her husband, resulting in his floating, and to include Clarke in the charges. Kane cites Penal Code 1 and sentences her death. He whispers to her that he chooses to do anything to keep the human race alive. She counters and says she chooses to do anything to make sure the human race DESERVES to stay alive.

Abby is put in the same cell Clarke was in. She notices Clarke's sketches.

Clarke wakes on the forest floor the group is all asleep around her and is fascinated by the bioluminescent flowers. Finn is also awake and has gone down to the river for a canteen of water. She drinks. Finn points out a footprint of something bipedal. She says shes read nothing about bipedal animals in that area.

Cece goes to Kanes quarters to plead for the life of her best friend. He says hes the only one who is willing to do what it takes to save humankind. Cece begs for mercy. Kane says they cant afford mercy.

Bellamy wakes Wells in the middle of the night and leads him into a clearing in the forest at gunpoint. Bellamy says he isn't going to shoot him but wants The 100 to think that he has. Bellamy wonders why Wells is behaving the way he is, since his father had banished him. He encourages Wells to take off the wristband. Wells refuses and Bellamy gives a signal whereby three thugs grab Wells, hold him down, and force off the wristband.

Abby is looking out the portal at Earth when the guards come to get her. She is dragged to an airlock. Cece hugs her. As the guards separate them, she asks Cece to watch over Clarke. Abby shrugs off the guards and walks in to the airlock herself. As the doors close, she tells Jackson to work with Sinclair to reverse engineer the wristbands to see if they can be used for communication. As Kane nods to Shumway, the Chancellor hobbles in and declares Abby pardoned. He tells Kane he will deal with him later and demands that Shumway open the door. Abby walks out and tells an orderly to take the Chancellor back to bed.

The group has to ford a wide gap over a ravine. Finn is on a precipice, holding on to a vine and is hesitant to swing across. Jasper encourages him but notices Octavia watching them. Jasper offers to go instead and Finn hands him the vine. Jasper makes it across to the cheers of the others and finds a deteriorating sign indicating Mount Weather. A spear comes from nowhere and pierces Jasper in the chest. The group crouches for cover. Clarke concludes that they are not alone.