Lieutenant Irene Lamont was played by Darren "Kolchak" McGavin's real-life wife Kathie Browne.

Kolchak's Mustang is given the nickname "the Yellow Submarine".

This is the second of only two episodes in the series in which Ron "Uptight" Updyke does not appear, the other is episode #2 "The Zombie".

The Sentry:
Craig Baxley makes his second appearance as a Kolchak monster, with his appearance as the "Sentry". Previously he played "Mr. R.I.N.G." in episode #12.

The basic plot of this episode is similar to the basic plot of Star Trek's “The Devil in the Dark.”

Carl: (opening narration) This is one story I may not get to file in person, so I'll have to talk fast because it's after me.

Kolchak: Howard Kemper was a good worker. He did what he was told. At least, that’s what people would say about him at his funeral.

Kolchak: Ten a.m. one day after the death of Howard Kemper. In the same underground complex, only this time Sector M. Business as usual, all except for journeyman electrician Larry Coogan. Coogan had complained to his friends that he didn’t like working so far underground. He said it felt like working in a tomb. Today he would learn how right he was.

Lt. Irene Lamont: Did a guy come in here wearing a seersucker suit, with red hair?
Receptionist: There was a Mr. Kolchak. I believe he was with a nickel firm in New Mexico.
Lt. Irene Lamont: He’s got nothing to do with nickel. He’s the proverbial bad penny.

Carl: Where is sector M?
Chapman: Have they changed the alphabet?!?
Carl: No...
Chapman: Well, then, M comes before R. Sector M is on the way to sector R!

(After goading Tony into a fury.)
Carl: Don’t yell like you always do. It’ll rile your bile.

Carl: You know, if all the film that I’ve shot that’s been confiscated by the cops were laid end to end, I’d have enough film to shoot War and Peace – including a travelogue and a cartoon.

Reporter (Brian): (in response to Carl's treatment of Lt. Lamont) Hey, ease up on her Kolchak, she's just doing her job.
Carl: Yeah, sure yeah. So was Adolph Eichmann.

Carl has himself delivered to Merrymount in a large packing crate marked “precision instruments.” His friend who delivers him enters through the lobby. Merrymount is essentially a specialized warehouse for long-term storage. It would have a loading dock and a freight elevator and would not bring packing crates through the lobby.

Carl removes one of the agates from their rocky vesicle and examines it, confirming his theory about it. Then he puts the agate onto the desk and puts the rock containing the vesicle into the golf cart so that he can return the agates to Sector R where Verhyden found them. But he never returns his sample to the vesicle. One assumes his plan was to return the agates and hope that this act placated the monster, but so, why not return all of them, or at least all that had survived Verhyden’s attention?

Seeing a corridor blocked by a guard station, Carl wonders aloud if that client might be a tall fellow with a tall white hat, stars and stripes and a white beard named Sam. He’s referring to Uncle Sam, a personification of the United States, and by inference suggesting that the client is the Federal government. Uncle Sam first appeared during the war of 1812, but actual drawings didn’t appear until fifty years later. Artists commonly depict Uncle Sam as a stern older man wearing a flared white top hat, sometimes decorated stars and stripes, a blue frockcoat, white shirt and red bowtie, and white and red striped pants. Variations exist, but the top hat is always present and the clothing always incorporates the colors and design elements of the American flag.

The bouncing camera work in shot from Carl’s perspective, looking back down a corridor so long the viewer cannot be sure what’s at the other end, does a nice job of heightening the tension of Carl’s flight.

The lizard suit is rather absurd looking and the director would have created a better effect had he kept the lizard largely off camera, just a claw here or a flash of teeth there. Such brief glimpses of the predator worked well in, for example, Alien, where they kept the viewer wondering until the final reveal: just what is this thing?