Secrets Of The Pyramids: Experts explore the similarities between huge pyramids across the world. Could extraterrestrials have influenced their construction and design? (S4, ep 6)
The Nasa Connection: Experts open up NASA and secret government files. Can they find proof of alien contact in the recent or ancient past? (S4, ep 5)
Aliens And Mega-Disasters: Did Mother Nature cause the volcanoes, earthquakes and floods of ancient times? Or could aliens have been responsible? Experts investigate. (S4, ep 4)
The Greys: Experts investigate the 'greys' - mysterious beings with big heads and eyes found carved into rocks. Who are these strange figures and what inspired them? (S4, ep 3)
The Doomsday Prophecies: Experts scrutinise the Maya Calendar, which predicted the world would end in 2012. Could it have anticipated the arrival of an extraterrestrial god? (S4, ep 2)
The Mayan Conspiracy: Experts investigate startling evidence suggesting that the Ancient Maya conspired with aliens. Was this how they acquired their knowledge of astrology? (S4, ep 1)
One Horse Open Sleigh: An antique horse-drawn sleigh arrives at the shop needing a complete overhaul for the holidays. The Pawn Stars' Rick Harrison throws a Christmas party.
Clueless: A stumped Rick calls Danny Koker for help when a mysterious scooter turns up. A dentist brings in a 1920s X-ray machine. But is it too dangerous to restore? (S4, ep 24)
Bombshell: The team take on the tough restoration of a unique wheelchair made from bits of a 1940s B-17 bomber. Plus, Kelly creates a risque anniversary surprise for Rick. (S4, ep 23)
Break In: A huge and heavily-damaged safe that hasn't been opened in years is dropped off at the shop. Can Rick crack the code to reveal its mysterious contents? (S4, ep 22)