The Truth Behind... — Season 4 National Geographic Ended 2 Episodes · Premiered October 4, 2015 · Ended October 5, 2015 ← Season 3 All Seasons Episodes E01 Crystal Skulls & Crop Circles Mon, Oct 5 2015 1:00 AM GMT+0000 60 min ▶ No synopsis available. E02 Zombies & Monsters Tue, Oct 6 2015 2:00 AM GMT+0000 60 min ▶ No synopsis available. ← Season 3 All Seasons
