Lost in Space (1965–1968)
3 user 1 critic

Deadliest of the Species 

The robot falls in 'love' with an evil female robot sought by two aliens.


Don Richardson


Robert Hamner, Irwin Allen (created by)




Episode complete credited cast:
Guy Williams ... Prof. John Robinson
June Lockhart ... Maureen Robinson
Mark Goddard ... Maj. Don West
Marta Kristen ... Judy Robinson
Bill Mumy ... Will Robinson (as Billy Mumy)
Angela Cartwright ... Penny Robinson
Jonathan Harris ... Dr. Zachary Smith
Ron Gans Ron Gans ... Alien Leader (as Ronald Gans)
Lyle Waggoner ... Mechanical Man I
Ralph Lee Ralph Lee ... Mechanical Man II


The robot falls in 'love' with an evil female robot sought by two aliens.

Plot Summary | Add Synopsis

Plot Keywords:

talking backwards | See All (1) »


Not Rated | See all certifications »




Release Date:

22 November 1967 (USA) See more »

Company Credits

Show more on IMDbPro »

Technical Specs


Sound Mix:

Mono (RCA Sound Recording)



Aspect Ratio:

1.33 : 1
See full technical specs »

Did You Know?


The "electronically recorded message from the Zeta Galaxy Law Enforcement Bureau" that the Jupiter 2 receives at the beginning of the episode is actually the phrase "Space capsule Alpha seven-eight-four has been pulled out" (that the Alien Leader says moments later in the show) spoken backwards. See more »


Throughout this show the Robot can be seen clearly walking like a Human. More than shows before. See more »


The Robot: Danger, Will Robinson! Danger!
See more »


Featured in Pioneers of Television: Science Fiction (2011) See more »

Frequently Asked Questions

This FAQ is empty. Add the first question.

User Reviews

Silver Alien Invader Show That Was Shown Out Of Production Order
1 June 2007 | by StuOzSee all my reviews

Episode eleven in screening order but episode four in production order (after Condemned Of Space, Hunter's Moon and Space Primevals). In production order, this was the first of several year three shows with silver skinned alien invaders. These invaders, one played by Ron Gans, are after a deadly female robot...who the Robinson robot falls in love with.

This is a half silly story which many fans think was made mid-season when things slowly started getting less "serious" but in reality it was made very close to the start of year three. It is a bit of a surprise that Irwin Allen would produce something this camp at the start of a season that was attempting to be more "serious" than the previous season. Who knows what happened?

Despite a sometimes silly story, this is not done in the same tone as year two at all. Action, ray gun battles at the campsite, explosions, Jupiter 2 space travel in the teaser, a death threat in the teaser, this was not year two at all. Interestly, when alien Ron Gans attempts to be serious with John and Don, it is a little hard to take him too seriously. Blame the writer not Gans.

I refuse to comment too much about the robot love story. I am sure some other user will comment on that side of things. Let me just say that pushing this hour back to episode eleven was a good thing. Deadliest Of The Species is not as bad as many would think but it is just not good enough to be shown at the start when all effort was being made to improve Lost In Space.

4 of 6 people found this review helpful.  Was this review helpful to you? | Report this
Review this title | See all 3 user reviews »

Contribute to This Page

Free Movies and TV Shows You Can Watch Now

On IMDb TV, you can catch Hollywood hits and popular TV series at no cost. Select any poster below to play the movie, totally free!

Browse free movies and TV series

Stream Trending TV Series With Prime Video

Explore popular and recently added TV series available to stream now with Prime Video.

Start your free trial

Recently Viewed