The Vikings founded a society in Greenland which would last for almost 500 years. Then, quite suddenly, it disappeared. What happened?

Icelandic historian Valur Gunnarsson travels through southern Greenland as he attempts to solve the greatest mystery in Nordic history. He navigates icefloes on an open boat, meets the locals, stays with a modern-day Norse settler on a reindeer farm and examines the church where the last Viking wedding was held before everything went dark. Was it climate change, plague, class-struggle, trade wars or foreign invasion that did them in? Did they try to leave before it was too late? And if so, where did they go? The answer to the riddle might just tell us something about how to navigate our own perilous times.