I take no credit for this upload.  All of these episodes have been uploaded, previously.
Two things: I downloaded a couple of episodes and the files were corrupt.  Second, I enjoy
this series and don't like fishing around for individual episodes.  I would presume there are others who would prefer to download the entire season. So these are all episodes of Ancient Aliens, Season 18 - MP4 format.

Ancient.Aliens.S18E01.The.Discloure.Event.mp4
Ancient.Aliens.S18E02.Mystery.of.the.Standing.Stones.mp4
Ancient.Aliens.S18E03.Beneath.the.Sacred.Temples.mp4
Ancient.Aliens.S18E04.The.World.on.Alert.mp4
Ancient.Aliens.S18E05.Recovering.the.Ark.of.the.Covenant.mp4
Ancient.Aliens.S18E06.Secrets.of.the.Star.Ancestors.mp4
Ancient.Aliens.S18E07.Alien.Air.Force.mp4
Ancient.Aliens.S18E08.The.Shadow.People.mp4
Ancient.Aliens.S18E09.Decoding.the.Dragon.Gods.mp4
Ancient.Aliens.S18E10.The.Time.Bender.mp4