The contrast could not be starker when it comes to the school's Masquerade, where tickets cost $10,000 a piece. Waverley could never find that sort of money so she isn't planning on going. But then one of her classmates, Caroline gives her a ticket and loans her the fancy gown she was going to wear on the condition that Waverly pretends to be her (being a masked ball, no one will know that it's really Waverly in the gown0. And so Waverly find herself sneaking in, under disguise.
That's when things start to go off the rails. Waverly finds herself witness to a murder and uncovers a plot to take over the world, being led by the headmaster of the Academy. It's a plan that that kicks off when the lights go out all over the world because of a solar flare. With time running out, Waverly and her friends must find a way to stop the plans, all while dodging a fabulous party that is taking place around them.
The plot is absurd, but gains gravitas (and/or gets weighed down) by including lots of biting social criticism. It's heavy-handed stuff. The leaders of the school and its supporters are connected with all the sources of wealth and power (politics, finance, technology, etc.) while Waverly and her gang of scholarship misfits are neuro-divergent, LGBT, and minorities. It is literally the kids against the 1%. That doesn't always work and there are several unintended humorous moments. But occasionally, as when Waverly has her climactic showdown with the headmaster, some rather thoughtful dialog emerges and deep questions get asked.