Let's say you're a massive interplanetary corporation that's sending a ship into space. It would be irresponsible to do that without having a company man on board, right? Without someone keeping an eye on things, the crew might go rogue or try to escape a killer alien. And, as Ridley Scott reasons, it's "better if the company man is an AI [and] no one aboard knows who the AI is."

From Ash in Alien to David in Prometheus, Scott has always been a fan of keeping an android on his spaceships. Originally inspired by HAL 9000 in 2001: A Space Odyssey, these AI creations have been about answering the fundamental questions behind why a company would build an artificially intelligent creature in the first place and what their purpose would be, Scott says in the video above.

The director's latest artificial crew member, for Alien: Covenant, is Walter (played by Michael Fassbender). He's created with eerily possible technology—3-D molds, a touchscreen to monitor his vitals, an outsized memory chip as a brain—but Covenant will challenge the idea of whether or not humans should use tech to create something that acts like a person. “Once it thinks, you’re in trouble,” says Scott. “By the time he’s thinking, you’re way behind the game, dude.”