Archaeologists in Croatia discover the remains of a mass grave dating back centuries. Experts immediately descend on the site armed with theories ranging from a deadly plague to war. But what they discover is much worse than they ever expected. Secrets In The Ice series 3 goes to the most remote, cold, and inhospitable places on the planet to reveal great mysteries that were once frozen in time. Merging CGI re-creations, advanced scanning technology and scientific research, the series investigates the curiosities that have been lost for millennia, or never seen before. It explores how and why these secrets ended up in the most desolate and distant corners of the planet and contemplates what may still be concealed in the frozen depths.