The Best Alien Movies on Showtime

What it's about: The Borg, a relentless race of cyborgs, are on a direct course for Earth. Violating orders to stay away from the battle, Captain Picard and the crew of the newly-commissioned USS Enterprise E pursue the Borg back in time to prevent the invaders from changing Federation history and assimilating the galaxy.

Where to Watch: Available to stream on a popular subscription service (Showtime), stream on a popular TV everywhere service (Showtime & Epix) & rent or buy from $2.99 on 9 services (iTunes, Google Play & 7 others).

What it's about: A teacher opens a time capsule that has been dug up at his son's elementary school; in it are some chilling predictions -- some that have already occurred and others that are about to -- that lead him to believe his family plays a role in the events that are about to unfold.

Where to Watch: Available to stream on a popular subscription service (Showtime), stream on a popular TV everywhere service (Showtime) & rent or buy from $1.99 on 8 services (iTunes, Google Play & 6 others).

What it's about: When contact is lost with the crew of the first Mars expedition, a rescue mission is launched to discover their fate.

Where to Watch: Available to stream on a popular subscription service (Showtime), stream on a popular TV everywhere service (Showtime) & rent or buy from $2.99 on 7 services (iTunes, Google Play & 5 others).

What it's about: Telly Paretta is a grieving mother struggling to cope with the loss of her 8-year-old son. She is stunned when her psychiatrist reveals that she has created eight years of memories about a son she never had. But when she meets a man who has had a similar experience, Telly embarks on a search to prove her son's existence, and her sanity.

Where to Watch: Available to stream on a popular subscription service (Showtime), stream on a popular TV everywhere service (Showtime) & rent or buy from $2.99 on 8 services (iTunes, Google Play & 6 others).

What it's about: In medieval England, Merlin and King Arthur banish the evil enchantress Morgana and her son Mordred to the ends of the universe as Morgana vows revenge. In present day, Knights descendant Penn doesn't take much stock in the legends of his supposed ancestors, even as the descendants meet in Thailand to practice fighting. But when Morgana and her son return to earth, armed with alien technology and hell-bent on destroying every last descendant of King Arthur and his knights, Penn must to come to terms with who he was born to be, and bring together the new Knights of the Round Table to save themselves and the earth from Morgana's total vengeance.

Where to Watch: Available to watch free online (Tubi TV), stream on a popular subscription service (Prime Video & Showtime), stream on a popular TV everywhere service (Showtime) & rent or buy from $2.99 on 6 services (iTunes, Google Play & 4 others).