For a long time, scientists have been discussing the Cambrian explosion that occurred about 540 million years ago. At that time, a great variety of life forms appeared on Earth. Earlier rocks describing the pre-Cambrian period did not show such diversity of life. However, scientists learned how to read these rocks and discovered a stunning “lost world” with astonishing forms of life. Paleobiologist and astrobiologist Martin Brasier invites listeners to set off on a thrilling journey into the past—something that was hidden from us and truly challenges the imagination.