Disc.History+1 Rome's Great Wall. The Roman Empire built Hadrian's Wall to guard its frontiers: new discoveries reveal who the Romans were trying to keep out with this 72-mile-long megastructure. S4, Ep12 2026-04-02 Mystery Of Planet 9. Scientists have discovered evidence of a mysterious ninth planet on the very edge of our solar system, could its moons support extra-terrestrial life? S5, Ep1 2026-04-02 A President's Close Encounter. Geysers are discovered on a frozen moon, NASA redirects a probe on a mission to find proof of life, and a future US President is eyewitness to a UFO. S3, Ep3 2026-04-02 Fire In The Cockpit. Experts investigate to see if the fire on Apollo 1 that killed three astronauts was a cover-up. Was it a tragic accident or part of the moon landing conspiracy? S1, Ep1 2026-04-02 Genghis Khan's Tomb. Josh Gates journeys into the heart of Mongolia in search of the fabled lost tomb of Genghis Khan. He examines historical evidence, facts and myths. S2, Ep6 2026-04-02 Skinwalker Valley. Phil and Jess investigate Utah's Uintah Basin, a region teeming with paranormal activity - including cattle mutilations and reports of shape-shifting creatures. S4, Ep7 2026-04-03