After four centuries of occupation and leadership, the Romans left Britain in 410 AD, and the island's fate was left hanging in the balance. History teaches that in the 5th century, the country descended into a tumultuous and violent period known as the Dark Ages, leaving the nation vulnerable to invading Angle and Saxon hordes from northern Europe. With a nation divided, a great leader known as King Arthur emerged, uniting the lawless lands to fight off invaders – or at least that's what the fragmentary historical texts suggest. The truth is, no one really knows what happened, and this pivotal moment in history has been shrouded in mystery – until now.

The key to Professor Alice Roberts' quest is the excavation of a stone palace complex on the Tintagel peninsula in Cornwall, England – long believed to be the birthplace of the King Arthur legend. More than folklore, was Arthur, in fact, ruler of a prosperous and sophisticated trading village and the heroic defender of the native Britons against the invading Anglo-Saxons?

Stories about drug use by Hitler and German forces during World War II have been widely told. What's less well known is the Allied commanders' embraced pharmacological "force enhancers" as well. By 1941, rumors about Nazi soldiers using a "super-drug" identified as the methamphetamine Pervitin were confirmed, and Allied commanders launched their own classified program to find the perfect war-fighting drug.

During the war, one in three Allied soldiers were incapacitated without a physical scratch on them. Modern weapons and warfare proved so terrifying that almost as many men were shredded by combat fatigue and shell shock — now known as Post Traumatic Stress Disorder (PTSD) — as by bullets and shrapnel. Allied commanders believed Benzedrine, an amphetamine similar to Pervitin, was the answer, hoping the amphetamine would defeat not just the need for sleep, but anxiety and fear among troops. How this drug affected the course of World War II is an ongoing controversy.

In Secrets of the Dead: World War Speed, join historian James Holland on his quest to understand how the use of amphetamines affected the course of World War II and unleashed "the world's first pharmacological arms race."