Two treasure hunters have uncovered a long-lost hoard of Knights Templar relics that could rewrite history; using cutting-edge methods, they set off on an expedition to reveal the dark secrets behind this mysterious treasure.

The black obsidian chalice, the most stunning relic in Hamilton and Carl's collection, is examined. The pair then head to Portugal to hunt for clues about the chalice's creation. Returning to the UK, the duo investigate its purpose.

Treasure hunters travel to the Holy Land to find out if their prized sword once belonged to the Grand Master of the Knights Templar; cutting-edge archaeology reveals a network of hidden tunnels in Jerusalem with ties to the Bible's greatest relics.

Exquisitely shaped from marble, the libation vessel is Carl's favourite piece in the hoard. They investigate whether its four carved heads could be depictions of John the Baptist.

A look at what is arguably the most intriguing item in Carl and Hamilton's collection: the 15th century reliquary casket. Although originating from a later period, a series of engravings on it appear to make veiled references to Templar beliefs.