Astronomers try to reconstruct how the universe went from a smooth, nearly featureless fireball to the web of galaxies, stars and planets we see today. The film follows scientists working with data from the Planck satellite, which mapped the faint afterglow of the Big Bang, the cosmic microwave background, in more detail than any previous survey. Researchers explain how tiny temperature variations in that ancient light correspond to the seeds of every galaxy cluster now visible in the sky, and supercomputer simulations show dark matter scaffolding pulling ordinary gas into the filaments and clumps that became the cosmic web. Interviews with cosmologists lay out the case for dark matter and dark energy as the invisible majority of the universe's contents, and the film walks through how competing models get tested against the Planck data. The result is a plain account of how a picture of the infant universe, barely a few hundred thousand years old, lets astronomers work forward to explain the galaxies, stars and planets that eventually formed.