“Unity Day” is episode nine of season one of The 100.
Unity Day is a celebration of when the original stations joined together to form the Ark, although according to Finn what is said to have happened on that day is not exactly accurate. At the end of the previous episode,
“Day Trip”, it was revealed that there were only enough drop ships to get about a third of the Ark’s inhabitants back to the Earth, and that the newest Council member, Sydney, and a former Chancellor herself, was the one who tried to have Chancellor Jaha assassinated.
When a bomb is detonated during the Unity Day pageant, some Council members are killed, and suspicion quickly falls on Sydney. Interestingly, at the beginning of the series it seemed like Kane was the one plotting to get ahead on the Ark, but his character has changed quite substantially. I had thought it would be longer before she was revealed. It’s also really unclear as to what Sydney’s motivations are.
Finn and Clarke try to make peace with the Grounders.