 So, Guy Raz, tell me what you've got for us today on how I built this. Sure. Well, the writers that you talked to really focused on world building. And my guest today, Cody Finke, he focuses on the materials that we use to build our world. Ooh, how so? His company, Brimstone, has developed a new way to make cement that doesn't release as much carbon into the atmosphere and actually gets rid of it. Ooh, how does he do that?