Angels And Aliens: Biblical texts describe winged creatures carrying messages from the heavens. But are angels merely the product of the imagination - or do they really exist? (S2, ep 8)
Creatures Of The Deep: Experts investigate whether alien life forms are thriving in our seas, following Russian cosmonauts' discovery of living plankton in space. (S8, ep 7)
Alien Messages: Could extraterrestrials have left us clues to the universe's mysteries? Experts investigate cryptic puzzles that might have been left by ancient aliens. (S7, ep 7)
Treasures Of The Gods: Across the world, there are stories of treasures that have been lost for centuries. Could these ancient relics have been hidden by extraterrestrials? (S6, ep 7)
Von Daniken Legacy: A look at the controversial ancient alien theories of Erich von Däniken, whose books have sold over 65 million copies worldwide. (S5, ep 7)
Aliens And Bigfoot: Ancient astronaut theorists hunt for evidence linking Bigfoot to alien species from the distant past. Could the ape-like giant be an extraterrestrial? (S4, ep 7)
Aliens, Plagues And Epidemics: Experts investigate reports of strange bronze flying ships spotted during the Black Death. Could aliens have brought deadly disease to Earth? (S3, ep 7)
Underground Aliens: From a cave in Ecuador said to hold tablets containing alien knowledge, to an underground city in Turkey, explore supposed extraterrestrial lairs. (S2, ep 7)
The Other Earth: Ancient Alien theorists explore world mythology as they investigate whether extraterrestrials could be responsible for our existence. (S8, ep 6)
Secrets Of The Mummies: Experts investigate the mysterious origins of mummification. Could this global practice be proof that aliens once visited Earth? (S7, ep 6)