After an encounter with Donovan, Rikuo retreats to Atlantis, only to be confronted by Morrigan and Bishamon. They capture him, and report to Pyron. Pyron wants to beam down to Earth, but Ship warns him he shouldn't, as most of his power comes from within the ship. Pyron ignore him and beams down, and attempts to convince Rikuo to join his side. However, a robot called Huitzil appears, having been activated the moment Pyron beamed down. Huitzil is programmed to protect his people from aliens, and he attacks and captures Pyron.

Pyron is taken away. Morrigan's group aren't that bothered over the fact that Huitzil intends to sacrifice Pyron, but Ship then contacts them. Ship reveals he's programmed to self destruct if Pyron is off the ship for a certain amount of time, and the resulting explosion will cause the Earth to be blown away! The Darkstalkers put aside their differences, and go to save Pyron. Meanwhile, Ship has Harry and Felicia beamed up, and Harry attempts to deactivate the self destruct. Back on Earth, Huitzil takes Pyron back to a temple, but is then attacked by Bishamon and the others.

Huitzil manages to get away with Pyron, and takes him to another temple. He tries to sacrifice Pyron again, but the Darkstalkers stop him, and Bishamon is able to hit him so hard that he explodes.

Pyron is beamed back to his ship, whilst Harry and Felicia are beamed back down. Morrigan tries to capture Rikuo again, but Bishamon stops her. Rikuo escapes, whilst Morrigan and Bishamon are beamed back up to the ship. Nobody knows that Huitzil has survived, and starts to pull himself back together...

Notes

-Most places, including the ADV DVD set, have this episode as the ninth one, whilst My Harry's in the Highlands is the eighth. However, according to the original air dates, Aliens Keep Out was aired as the eighth episode, whilst My Harry's in the Highlands was the ninth.

-Donovan can apparently read minds -Rikuo thinks he's not alone, and then Donovan tells him he isn't.

-Huitzil's voice actor, Ian Corlett, also voices Victor and Ship.

-In the first Darkstalkers game, Huitzil is bronze colored. In the game's sequel, Night Warriors, he's a light shade of blue. Seems the production staff decided to use his default color from Night Warriors instead of Darkstalkers like all of the other characters, for some reason.

-The ADV Out of the Shadows DVD set uses part of a shot from this episode on its cover.

-Ship breaks the fourth wall -he tells Harry and Felicia how "it all started in act one".

-Whilst Huitzil is seen pulling himself back together again at the end of the episode, he's not seen in the series again.

Errors

-The title card is spelt "Alien's Keep Out", when it should be "Aliens Keep Out".
-The ropes Morrigan summons are initially colored brown, but these change color to white later.
-When Pyron says "turn off your pleasure circuits", Ship lights up blue like he's meant to be saying something, but he's silent.
-Huitzil's flames are first colored red, but then change to blue.
-When Bishamon says the battle is not over, Rikuo's forehead is colored yellow instead of green. As the camera pans over, Bishamon's eyes change color from purple to blue.
-When Bishamon runs towards Huitzil, his sword is suddenly sheathed. It wasn't in the shot before this, and is unsheathed the shot after.
-The beams Pyron shoots Huitzil with are colored yellow, but during this shot, the beam is colored blue.
-When Huitzil grabs Pyron, either Huitzil is too big, or Pyron is too small.
-Bishamon's sword does not appear to be fully drawn during this shot.
-Part of Bishamon's helmet flashes blue during this shot.
-Harry's computer changes to a darker shade of gray between shots.
-When Felicia says "hurry, get us up there!", her mouth doesn't move.
-Morrigan's sleeves are skin colored during this shot.
-Why does Morrigan start climbing up the temple? Couldn't she just fly up?
-Bishamon's sword is colored brown instead of silver during this shot.
-Bishamon's arm is not fully drawn during this shot.
-During this shot, the forcefield effect is missing, making it look like Bishamon hits nothing.
-Morrigan's sleeves are skin colored again during this shot.
-Bishamon's eyes are colored white instead of purple during this shot.
-The above error happens again during this shot.
-During this shot, the wrong background is used -it should be a space background.
-The above error happens again during this shot.
-Bishamon is colored entirely red during this shot.
-During this shot, the effect for Morrigan's projectile is missing.
-During this shot, Harry's computer perfectly fits into the cabinet it's in, but during the next shot, it seems to have shrunk.