Symbologist Ashley Cowie is on a mission to find the world's most mysterious relics, and he's bringing a crack team with him to do so. He and Field Associate Kinga Philips make their first target the Lost Ark of the Covenant, the very vessel built by Moses to house the Ten Commandments. The Ark is believed to have mystical powers that the Israelites used to destroy their enemies, and world leaders - including Hitler - have sought the Ark in order to bend its awesome powers to their ends.
Ashley follows clues to the town of Lalibela, Ethiopia, home to an assemblage of churches hewn from the very mountain that surrounds them. Tales of light-haired, fair-skinned strangers who aided in this effort abound.
Ashley speaks to a high priest in one of the churches, but the priest is mum. But Ashley notices two symbols belonging to the Knights Templar: A double-headed eagle, representing the two cherubim of the Ark, as well as a Templar cross. In fact, the church in which they're standing is built in the shape of a Templar cross!
Ashley deduces that fair-haired strangers of local lore were actually European Knights Templar, who could've spirited the Ark to a stronghold in Italy. At the Castello della Maggioni, a Templar stronghold, the team speaks to the Grand Master, who denies that the Ark is lodged there, hinting instead at the cathedral in Chartres.
Ashley and Kinga fly to Chartres to investigate the cathedral. Kinga convinces a caretaker to let them explore the tunnels under the labyrinth on the cathedral floor, and in the dark, the duo feel their way for the holy relic. Ashley is thrilled when he comes upon a chamber with the exact dimensions of the Ark, but the compartment is sealed with both wood and stone. That much protection surely hints at something precious beyond, but Kinga and Ashley can't get through. With its terrible powers, perhaps it's best if the Ark remains imprisoned forever.
They are soon called to the Yucatan Peninsula in search of the Talking Cross, a Mayan artifact said to guide the people, at first benevolently. Later, however, the Cross became wrathful, and the Mayans sought to take it as far from their culture as they could.
In Xocen, Mexico, the village elder tries to dissuade them, but under Ashley's unrelenting curiosity, the tells them of a cave associated with the cross. Aided by locals who help hack through spiky plants and thorny cacti, they discover the cave. The find is unbelievable: nine hand prints, symbolizing the nine purifying children sent on the mission to hide the cross, on the western wall of the cave. The handprints represent the children, themselves, but also nine days of travel in a westerly direction.
They recreate that journey and find themselves in Yaxunah, the Mayan spiritual capitol. At Yaxunah's temple, they find a clue literally set in stone: a square altar with a round rock, symbolizing an underground, water-filled cave, or cenote, in the center. The cenote is where the Cross originally came from, and Ashely's hunch tells him that that's where it was buried.
Once in the legendary cenote. if they move even one rock, they could cause an underwater landslide that would suck them all into a deadly whirlpool. Ashley dives deeper and deeper to the end of a tunnel. He's sure the cross is behind this enclosure, but the treacherous nature of the cenote prevents him from moving any of the rocks. It seems the Mayans, expert divers, put the Cross in a place where it and humanity would be forever asunder.
The pirate Heracleo betrays team Spartacus, Caesar stabs Spartacus, Agron does an amazing spin down a rope, and Crixus and Naevia return to fight for the city. A real action packed sequence.
Caesar: spreading news and making everyone hate each other. When Crixus gets wind of his tale, he confronts Agron head-on.
Count all of this episode's zombie kills along with us.