Title: The Sandhog Murders
Air date: November 26, 1939
Plot summary: "Sandhogs", as it turns out, are the people who work underground, digging tunnels underneath rivers. As the plot opens, a visitor is underground with the men digging a tunnel under the river to the city. The shift ends, and everyone gets in the decompression chamber—and the pressure is instantly released, instead of gradually as required. Eight men die of decompression sickness, aka "the bends".
Cue Lamont Cranston, reading about the tragedy in the newspaper. It turns out that the contractor in charge, Pete Stockton, is an old friend of his. Pete is deeply disturbed by the accident and tells Lamont that he is getting out of the construction business and handing the contract over to a business rival, Joe Branley. But Pop Burkey, foreman at the construction site and once partner to Pete's father, tells Lamont that the "accident" wasn't an accident, it was the evil work of Branley, who wants that contract. Lamont and Margot proceed to investigate.
Tropes:
- The Dog Was the Mastermind: Is the killer Branley, who is hostile and confrontational to Lamont when questioned and has a stereotypical "bad guy" manner? Nope, it's cheerful old Pop Burkey, who blames Pete's father for the accident that he suffered back in the day, and also blames Pete's father for stealing his girlfriend, something that wasn't mentioned in the episode.
- Drowning Pit: A slightly unusual example. Lamont and Margot are trapped in the tunnel, and the pressurization machine has been rigged to increase the pressure in the tunnel until it explodes, letting the river in and drowning Lamont and Margot. In fact, it actually does explode, but as the end of the episode reveals they found an air pocket and eventually escaped via the pressure chamber.
- Face Death with Dignity: When it seems that Lamont and Margot are truly screwed, as they are trapped in the tunnel which is about to explode, they do this. Margot tells Lamont "I'm not afraid to die," he tells her how lovely she is, and they reminisce for a bit about their past adventures.
- Instantly Proven Wrong: Margot worries that going into the tunnel while bad guys are about is a bad idea, and points out that someone could overpower Pop who is standing guard above. Lamont tells Margot "don't be silly" and is in the middle of saying about Pop that "he's not going to—" when the lights cut out and they wind up trapped. Subverted when the ending reveals that Pop is the bad guy.
- Naïve Newcomer: Mr. Pine, the visitor to the tunnel dig in the opening scene. His lack of knowledge about tunnel work requires one of the workers to explain to him and the audience about how the decompression chamber is necessary to avoid fatal cases of decompression sickness. This sets up how Pine and the seven workers die immediately after this conversation when they get in the chamber.
- Narrator: Sometimes the MC that introduced the show would go on to set the scene with narration, if required. In this episode the announcer does just that, narrating the opening scene and establishing that it involves "sandhogs" digging a tunnel under the river.
- Reports of My Death Were Greatly Exaggerated: Commissioner Weston is caught by surprise when Lamont and Margot, presumed dead in the tunnel cave-in, turn up very much alive with their tale of escaping via the pressure chamber. When Weston asks why they waited so long to show up, Lamont says that they wanted to read their own obituaries.
