Lost in Space Season 3 Ending Explained

This article contains spoilers for the ending of Netflix’s Lost in Space.

After three thrilling seasons, everybody finally made it to Alpha Centauri! But, as Lost in Space season 3 reveals, just because you make it home, doesn’t mean everything is okay. The final moments of Lost in Space season 3 resolved several plot points at once, and up-ended a lot of assumptions you might have had about the alien robots up until this point.

Here’s exactly how Lost in Space season 3 ended, and what it means.

Hastings has the key to the defensive shield 

When the Robinsons finally arrive at Alpha Centauri, they know SAR and the hostile alien robots are hot on their tail. What they need is an EMP shield to knock out the attacking robots’ ships. But, in order to do that, they have to get a verbal command from Hastings (Douglas Hodge). Don’t remember who this guy is or why he’s in jail? Back in season 2, Hastings tried to take over the Resolute using command codes that were given to him by Maureen Robinson. Why would she do that? Well, although he was offscreen in season 1, Hastings basically blackmailed Maureen into getting those codes, in exchange for getting Will into the 24th Colonist group. 

In season 3, Hastings is once again involved in some shady stuff, but like Adler before him (who died in season 2) Hastings is eventually killed. This means that, for the most part, all of the human enemies of the Robinson family are dead by the end of season 3.

Half the robots turn out to be good

Without a doubt, the biggest twist in Season 3 is the revelation that Will Robinson’s robot, and Scarecrow from season 2, “weren’t flukes” insofar as the idea that humans and alien robots can have special bonds that…well…aren’t actually that special.

The idea that the robots can change their minds and end-up defending humans is certainly an 11th-hour twist in Lost in Space. When Penny decides to show one of the attacking robots mercy, it suddenly changes its mind about who its enemy is and gets named “Sally” for its trouble. Several of the kids are able to duplicate this process, creating an army of robots fighting for the humans against SAR and the alien robots who don’t like humans. This twist might scan as a little corny, but the truth is, for the most part, it works. For the entire series, what Lost in Space has demonstrated is that what made Will different was that he trusted the robot as a leap of faith, a leap that everyone else (except maybe Adler) was willing to make. 

So, did Lost in Space say the solution to the robot “war” is simply to say “all you need is love/trust.” Yes. Did it work? Yes.

The Robot Puts His Katra In Will’s Heart

Okay. Okay. We all know that the “katra” is the Vulcan concept of a soul and that’s from Star Trek, but hey, it really feels like that’s what happened in Lost in Space, right? When the OG robot saves Will by jump-starting his heart via lightning, it seems to destroy the robot, turning him to ash. But, because Will now has a mechanical heart, we later realize the robot downloaded his entire consciousness into Will. So, later, when SAR stabs Will in the heart (for a second time this season) it backfires. The good robot’s programming takes over SAR, and uses SAR’s body to become a new version of itself.

To be clear, we’ve never seen a robot hop bodies like this in Lost in Space, and it’s not entirely clear how the robot was able to overtake SAR’s personality, but whatever!

Dr. Smith’s fate 

Oddly, one of the most bittersweet moments in the ending of Lost in Space season 3 is the moment when Parker Posey’s Dr. Smith decides she will not kill Commander Radic. To be clear, Radic is the only person who had definitive proof that Smith (really Jessica Harris) forged her way onto the Resolute and was nearly arrested before the robot attack. In season 3, Smith could have killed Radic, and protected the truth of her shady backstory, but, thanks to a late-in-the-game moral intervention from the OG robot, she doesn’t.

Lost in Space ends with a cozy family get-together that lacks Dr. Smith. In the end, she turned herself in and was put in jail. Maureen visits her toward the end of the finale and says Smith should get in touch when she gets out. Essentially, Lost in Space has a happy ending, and its greatest anti-hero, Dr. Smith, doesn’t die. Smith doesn’t get off scot-free or anything, but it’s easy to squint and imagine a future when she gets out of jail and starts mixing things up on Alpha Centauri. 

Lost in Space Season 3 is streaming now on Netflix.