“Echoes” is episode one of season four of The 100.
In the season three finale, “Perverse Instantiation: Part 2”, Alie’s reason for why she was assimilating humanity into the City of Light was revealed – it was to protect the human race. Similarly, she had caused a nuclear holocaust for the same reason, protecting humanity, in that case from overpopulation. This was the ‘perverse instantiation’ of the title – her methods were a little bit askew from her motives.
The reason that humanity needed protecting on this occasion were that the nuclear power plants which hadn’t been destroyed in the nuclear exchange (caused by Alie) were melting down, which will wipe out the human race in a matter of months as the surface becomes uninhabitable. Alie had some really serious issues when it came to judging what was the proper response to solve a problem. Clarke still activated Alie’s kill switch.
This episode opens immediately after the events of the last. Octavia, who has just killed Pike in revenge for the death of Lincoln in “Stealing Fire”, is climbing down the tower in Polis. Indra, who had been put on the cross, is being taken off it and it looks like there are a few dead. Clarke and Bellamy exit the tower a more normal way; Clarke is uncertain about how people will react and Bellamy says they need to know it’s the truth. Clarke says it is, but they don’t tell anyone for now. So they can have a break from saving the world. Clarke promptly gets blamed for the deaths though. The Grounders are blaming the Arkadians for the chip.
In Arkadia Harper, Monty and Jasper are celebrating but Raven wants to get the mainframe back up and running. Raven seems to have got a permanent benefit from Alie’s influence, in regards to her coding skills. She also chases the others out whilst she fixes the radio. Jasper is still not in a good place and steals a gun. When Raven gets in contact with Bellamy, he and Clarke ask her to look into the reactors. Quite how reactors could still be functioning after a nuclear war and this amount of time anyway is explained.
Roan is badly injured and the Ice People don’t want Skaikru to help him. The current leader of the army of the Ice People (who was in a cage in Mount Weather along with Bellamy) claims Polis on behalf of the Ice Nation, until Roan gets better. When one of the ambassadors objects, she kills her, and says that no Skaikru are allowed to leave Polis. Jaha is also, unsurprisingly, not popular. The Grounders also lack a Commander, although Clarke still has the Flame (which at the moment is kind of unusable). Taking control of Polis from the Ice Nation will require a war. Clarke tells the others that they don’t have time for a war – they need to heal Roan so that he can keep his promise to Clarke. Doing so will require a fair bit of subterfuge, given that the Ice Nation does not want help healing him.
Of course, it’s not going to be that easy, and Bellamy doesn’t quite get the brief respite from saving the world he wanted.