For decades, scientists have tried to unlock the secrets of ancient DNA. But life's genetic blueprint is incredibly fragile, and researchers have struggled to find DNA in fossils that could survive millions of years. Then, one maverick scientist had the controversial idea to look for DNA not in fossils or frozen ancient tissue - but in dirt. Join the hunt as scientists decipher the oldest DNA ever found, and reveal for the first time the genes of long-extinct creatures that once thrived in a warm, lush Arctic.