Mount Weather is under attack on The 100 Season 2 Episode 15. To see if your favorites made it through part one of the battle, watch The 100 online at TV Fanatic.
Bellamy has kept his promise to Echo and the Grounder prisoners, returning to the Harvest Chamber to free them from their cages. They will play an integral part in the battle ahead.
Clarke and Lexa are preparing the Grounder army at the doors of the mountain. Clarke goes over the plan, which includes four teams.
One at the Dam to blow the power (Raven/Wick), one at the mines to disable the Reapers and guide the prisoners to safety (Indra/Octavia), one inside the mountain (Grounder and Ark prisoners/Bellamy), and one at the doors (Clarke/Lexa).
Raven and Wick are setting detonators to blow the power source. Their plan goes awry when one of the bombs breaks, leaving them one short. They come up with a new plan, but it puts them in danger and they are caught in an explosion.
Ultimately, they do succeed in blowing the power, but the detonator at the doors fails. Sgt. Miller attempts to make it to the doors to detonate the charge, but also fails. Lincoln manages to shoot a flaming arrow that does the trick.
Lexa leaves to take out the shooters on the ridge and returns to tell the Grounders to stand down. She has made a deal with the Mountain Men for the freedom of the Grounder prisoners, but the deal does not include the Sky People.
She retreats, leaving Clarke to fend for herself.
Inside Mount Weather, Bellamy connects with Jasper, Maya and Monty. Cage has announced that the only radiation-free zone will soon be level 5. This does not bode well for Maya. They stay the course, but are horrified to find the Grounders gone from the Harvest Chamber and Maya's father dead.
Octavia refuses to retreat on Lexa's command. She tells Indra that she doesn't trust her. Indra renounces her as second and leaves her in the tunnel alone.
Clarke stares at the doors, also refusing to leave and in desperate need of a new plan.