It details how the Common Core got made, and how many of the things said about it ("internationally benchmarked", "state-led", "college and career ready", etc.) are hokum.
It covers a lot of ground, but I particularly like the interviews with two of the people who were asked to participate in the reviewing of the Common Core: James Milgram--the only mathematician or math teacher involved in any stage of the creation of the core, and Sandra Stotsky--who wrote the excellent pre-core, Core Knowledge-based, Massachusetts standards. Both of them refused to sign off on the Common Core standards.
Another critical moment, is when they show video of a hearing with a core participant who says flat-out that the core is not for STEM-oriented students and not for students aiming at selective colleges.
It's not as if the lead mathematics standards writers themselves didn't tell the public how low Common Core's high school mathematics standards were. In 2010, Jason Zimba, a lead writer, said the standards are "not only not for STEM, they are also not for selective colleges." [ Common Core Fails To Prepare Students For Stem (Denver Post) ]