Sworn to protect and preserve the Holy Blood of Christ, the Brotherhood of the Blood are a dark and mysterious sect. We go on a quest to shed light on a group shrouded in secrecy through the ages, revealing the extreme methods the Brotherhood used.

Inside Secret Societies investigates the mysterious secret society known as 'The Priory of Sion' that traces its roots back to the 12th Century and is believed to protect incontrovertible, if heretical, information about the marriage of Jesus Christ.

Exploring the secrets of The Assassins, one of the mostly deadly, notorious and secretive groups in the Medieval world, and discovering whether their skills and tactics been passed down and copied by today's Islamic terrorists.

Unearthing the secrets of a widespread criminal gang in the heart of Japan who are engaged in a variety of criminal activity including extortion, prostitution and illegal gambling.

We delve into the world of the most notorious white supremacist group in America – the KKK. Once having over a million members, today it's just a shadow of its former self. We meet real members and look at the impact of the group has had on America.

Inside Secret Societies uncovers what lies behind the history of the overwhelming military power of the Nazis - their strong belief in ancient mysticism, the occult, and even alien contact which fuelled their desire to rule as a genetically pure race.