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A mysterious invoice written by Harriet Tubman sends Justin deep into former Confederate territory to investigate whether a secret network of escaped slaves turned the tide of the Civil War in favor of the Union.

Justin’s journey to solve the mystery behind the death of famed 19th-century explorer Meriwether Lewis leads him deep into the secret land wars that almost changed the face of America.

An expert team of engineers use hi-tech explosions and state-of-the-art drilling rigs to tear through solid granite and build an 11-mile underground tunnel, one of the longest in the world.

Egypt's Black Pyramid is the strange, crumbling pyramid that collapsed before its pharaoh was ever buried here, and today, it's largely unexplored; special access to a hi-tech archaeological investigation reveals what went so catastrophically wrong.

Engineering failures are Icarus-like moments when our overreaching, greed and desire to conquer the impossible can cost not just reputations, but millions of dollars, the environment and lives. Each episode will focus on one disaster, looking at dramatic archive news footage of the disaster occurring and its devastating impact.

The sprawling city of Persepolis was the capital of the first imperial civilization that conquered most of the known ancient world; now, experts use advanced forensic archaeology to reveal the secrets behind Persia's mysterious and dominating metropolis.

See the ultimate guide to the Solar System from the dedicated people who sent spacecraft to explore the sun and the planets, and witness their astonishing tales of discovery as they reveal wonders never seen before.

The downfall of the powerful Maya city of Palenque continues to mystify archaeologists today; now, investigators gain rare access to explore lost tombs to reveal the truth behind this legendary city and the mystery behind its enigmatic queens.

From the raging inferno of the Sun to the icy beauty of Pluto, experts investigate the secrets that have lingered in the Solar System for billions of years in cutting-edge missions to infinity and beyond.

Whether trekking through the remote jungles of Cambodia in search of a legendary ape-man or exploring the secrets of the world’s largest cave system right here in the United States, the Expedition X team is taking viewers to the stranger side of the unknown.