Dr Smith seems improved with a little more proactiveness and courage to help by going into the antimatter world, this episode excellent masterpiece--juxtoposed with mideviel type between that short skirmish in the cave with the real John R. and imposter Don with flaming sticks. Still the 2nd and 3rd episodes gradually convert to too much goofy overexaggerated drama and foolishness with the robot. Just seems to ruin the melodrama of real science fiction. Still love the Lost in Space as whole because of the era of this program and cohesion in the family in outer space. The season remains my favorite, cuts to the chase, gloomy and not too much colorful comedy.

Best line of the whole episode takes place at 4:05 .... Don talking to Doctor Smith ... "maybe you can toss the salad or something" ... priceless!!

Good villan stuff here, If they used a few more of the crew. The robot would be good, but they had him horiziantal/ or verision ? don't know. Yes star trek with larzasus in the anti-matter hall; was a good fight! BOY HOWDY !! fer sure !! Good night thanks to the Jupiter 2 I can sleep tight !! nothing going to bite !! night

this was one of the best, very well written and directed. Anyway I've been watching this
show since it very first aired in the 60's and have watched the re-runs for many years
too. Never get tired of this watching this show.
My favorite part is where they cross over the bridge. I agree the robot is a little stupid here but that's the way he was in the 3rd season
he shows too much emotion and he's too human like.Great acting here by Guy Williams, but I'm sure Disney studios trained him. (he was
Zorro for those of you who have not seen the series).

Another episode that used to scare the wits out of me when I was a kid! That crazy dimensional bridge really creeped me out. It seems LiS had a cosmic storm every other episode -- if they weren't finding stuff in caves, they were running from a cosmic storm!!! Kinda explains why John and Don were perpetually working on weather stations!Neat that Star Trek also had an anti-matter double fighting himself in the doorway between dimensions. I always wondered how the anti-matter villains had all this knowledge about OUR universe, but we're so in the dark!Also, if the anti-universe is the opposite of ours, shouldn't crime be legal? So why is anti-Robot caged, and why isn't the guard caged, too? Best not ask!