We open to Ruby giving her mother's monument the run down of the past two seasons and after a few reveals and lampshading the naming choice of the writers, Ruby is off. It's the first day of the 40th annual Vytal Festival Tournament and its team RWBY vs. team ABRN. But while this battle occurs, there are shadows beginning to stir under the light of this event.

It's Team JNPR vs. Team BRNZ and Team SSSN vs. Team NDGO.

Starting the last episode ends, Ruby follows Weiss as she races across Vale to greet a woman who turns out to be Weiss's older sister, Winter. As the sisters begin their journey back to the school, they're interrupted when a drunkard picks a fight with Winter. He turns out to be Ruby's uncle, Qrow. Awesome fight and property damage ensue, until it's broken up when Ironwood shows up followed by Ozpin and Glynda. Later, Qrow, Ironwood, Glynda, and Ozpin have a meeting where a lot of harsh words ensue.

The first doubles match of the tournament puts Mercury and Emerald against Yatsuhashi and Coco. Later Qrow and Winter spend some quality time with their families.

Penny reveals to Ruby that she wants to remain at Beacon and mentions that she has a plan to make that happen. Yang and Weiss fight Team FNKI representatives, Flynt Coal and Neon Katt. Qrow and Ozpin discuss Ironwood's recent actions and Qrow asks Ozpin if he's chosen the "guardian" yet.

We open to Pyrrha getting her world rocked as Ozpin and co. tell her the secret history of Remnant. Later we start the opening of the singles matches with Yang vs. Mercury.

The episode gives a glimpse into the past about Cinder's motivations, how she recruits Emerald and Mercury, how she connected with the White Fang, and how she managed to steal the Fall Maiden's power. We also cut back to the present to see the immediate aftermath of what happened after Yang's victory against Mercury in the tournament.

Team RWBY rally around Yang when Ironwood tells her she's been disqualified then Qrow and Yang discuss Yang's mother. Jaune and Pyrrha have a heart-to-heart which distresses Pyrrha due to her confusion about Ozpin's offer. The next fight is confirmed to be Penny versus Pyrrha while Ruby finds herself confronting Mercury, who is supposed to be on his way back to Haven.

Mercury fights Ruby to prevent her interfering with Penny and Pyrrha's fight. The tournament match ends in disaster and Cinder hijacks the airwaves with a grim message for the world's audience. Roman and Neo sabotage the Atlesian military ships while the Grimm and the White Fang begin their attack on Vale.

War breaks out with battles occurring on the tournament field, the city and the school. Formerly adversarial tournament teams unite to fight the Grimm together while Ruby goes after a rogue airship that has turned on the rest of the fleet. Cinder's virus makes things worse by turning the robotic Atlesian army against both the city and its defenders. And then the Grimm Dragon appears...

On the airship, Ruby fights Roman and Neo while Ironwood joins Glynda and Qrow on the battlefield below. The students fight Atlesian Paladins while Blake confronts Adam in the school's cafeteria, leading to a showdown between Yang and Adam. Meanwhile, in the secret vault, Ozpin, Jaune and Pyrrha attempt to transfer Amber's Aura to Pyrrha... and Cinder shows up.

While Oobleck and Port oversee the evacuation, Ruby and Weiss hunt for the missing Jaune and Pyrrha. At Beacon Tower, Cinder appears to defeat Ozpin so Pyrrha fights her alone to try and save the tower. Ruby's arrival just in time to see the end of the fight triggers a mysterious power she didn't know she had. The episode ends with Ruby deciding to travel to Haven in search of answers.