Major Characters:

• The Shadow/Lamont Cranston
• Paul Bartow: Judge John Bartow's nephew who is in jail for embezzlement
• Marty Lagort: Paul's cell mate and convict.
• Peggy Sanders: Paul's girlfriend
• Edwin Bartow: Paul's stepbrother
• Judge John Bartow: Paul's uncle

Featured Agents:

• Margo Lane
• Commissioner Weston

Minor Characters:

• Prison Guard
• Prisoners
• Radio Announcer

Synopsis: (Warning! Contains spoilers!)
It is nearly midnight at the State Penitentiary, and the prisoners are fast asleep. All except two: Paul Bartow and Marty Lagort. Marty doggedly taunts Paul that he (Paul) has been framed for embezzlement and he is too scared to do anything about it. It seems that Paul's uncle, Judge John Bartow, has framed him for the crime and sentenced him to six years in prison. This same judge had also sentenced Marty to life, and he wants revenge. Marty tries to convince Paul to escape with him, but Paul decides against it; after all, he has only two years left in his term. Finally, they settle down. Marty spots a picture of Peggy Sanders, Paul's love, on the wall, and surprises Paul by letting him know how much he knows about her ("there are ways of finding out in prison", he tells him). Peggy is the ward of Paul's uncle, and is to marry Paul's stepbrother, Edwin Bartow, next week. Paul does not believe it. She loves only him. Marty goes on to insinuate that Paul's uncle is forcing her to marry Edwin. Taking the bait, Paul finally agrees to the prison break.

The next day, as the prisoners are led out to the exercise yard, Marty lets Paul in on his plan. Marty's prison mates will help cause a commotion to distract the guards. In the meantime, they will both head for the far wall leading to the watchtower. Marty gives the signal, and his friends start a fight. As they head for the tower, they are spotted by a guard who tries to stop them. Marty pulls out a knife and kills him, an act which horrifies Paul. They then remove a stone that has concealed an entrance to an old water main. This leads directly to a stream on the other side. At this point, Paul now has second thoughts about the escape, and decides not to go through with it. Not satisfied with his answer, Mary knocks him unconscious and escapes with him.

Driving down the road that night, Lamont and Margo listen to the radio announcer's report on Paul and Marty's prison break. Edwin, Paul's stepbrother, had called them to come see him. It seems that he fears that Paul will get his revenge against himself, Peggy, and his uncle. Lamont, who has known Paul before the embezzlement trial, won't believe that he is capable of murdering anyone. He is aware that the uncle, who doesn't sound like a very nice person, had put Paul in jail to get rid of him. They are about to talk about the embezzlement case when they are flagged down by Edwin with a flashlight. Edwin tells them that Paul is in the house with Peggy and his uncle. Paul has accused his uncle of forcing her to marry him (Edwin). Edwin claims that this accusation is false: Peggy really loves him instead of Paul (even if Paul had never gone to jail), and he would never double-cross his own stepbrother. Four and a half years in prison has changed Paul for the worse. Knowing that Lamont was friends with Paul, Edwin asks him to talk to him and persuade him to finish his prison term. Lamont agrees.

Entering the house, Edwin calls for Peggy but gets no answer. He deduces that she has locked herself in her room, as she cannot bear to see Paul's face again. Lamont suggests that Edwin tell Paul that he is here to speak to him. Edwin takes them to the library where Paul is confronting his uncle. When they arrive, they hear a terrible row between the two men, followed by some gunshots. Rushing in, they find the uncle dead and Paul missing. The window of the library is open. Lamont tells Edwin to call the police, though Edwin feels that it is too late for that now. Glancing out the window, Lamont notices that the drop from the window ledge to the ground is three feet, so Paul should have left footprints on the ground when he landed — except that there are no prints anywhere to be seen! That could only mean Paul is still in the house. That assumption is proved correct when they hear gunshots and Edwin's cries. They finally find him in the cellar. Edwin tells them that he had heard a noise in the cellar as he was calling the police, so he decided to investigate. It turned out that Paul was in there and tried to kill him, then escaped through a window. Lamont is now convinced that the Paul he once knew has changed for the worse. Suddenly they hear more gunshots, and Lamont tells them to get down. Lamont realizes that he's been hit and collapses, leading a horrified Margo to believe he's dead.

Lamont awakens to find Margo at his side. She tells him that Edwin had carried him up to Peggy's room to rest, and is now gone to fetch the doctor. As they talk, they hear muffled cries coming from Peggy's closet. Upon opening the door, Peggy herself tumbles out bound and gagged. Margo unties her, and she tells them her story. Peggy was downstairs when she heard a knock on the door. She answers, and finds herself staring at Paul and an ugly man. When asked if it was Marty, she replies that Paul did not call him by name. Paul seemed to act strangely, hardly recognizing her. He was more interested in seeing his uncle, and left to see him in the library after hearing his voice. The ugly man then clamped a hand over her mouth and chokes her unconscious. Lamont asks her if she knows that the uncle is dead. Peggy is shocked, but refuses to believe that Paul had anything to do with it.

Weston has now arrived at the scene of the crime and has concluded after an examination that Paul is guilty of murder. Peggy, like before, refuses to believe him. In her nervousness, she accidentally turns on a recording machine. Margo thinks she recognizes the voices on the machine. Edwin tells them that it is his hobby to record snatches of conversations with the machine just for the fun of it. The voices they are hearing now are Lamont and Margo conversing during a bridge game a year ago. Weston thinks Edwin's hobby is kind of silly. Returning to the original subject, Lamont thinks that Marty is responsible for the murder, but Weston does not buy that theory. Weston now asks Peggy, who had known Paul since their childhood, where he might hide. She does not know.

Later, Lamont asks Margo to watch the window to see if Peggy leaves the house. He knows that she was lying to Weston, and knows Paul's whereabouts. It is proof that she truly loves him. Margo spots her going out the side entrance and down to the ocean. Lamont tries to get up and follow her, but Margo insists that the only thing he's going to follow are the doctor's orders to get some rest. With that, despite his protests, she takes over his job!

Paul comes to and finds himself in a cave with Marty. His head is throbbing badly. Marty tells him that he (Paul) had brought him here, but Paul recalls nothing after the prison break. Marty reminds him that he's in a cave on the beach near his uncle's house, which rests on a cliff. Paul begins to reminisce about his childhood here with Peggy. Marty soon leaves to get them some food. Peggy emerges. She had waited for him to go so she can be alone with Paul. She tells him of his uncle's murder and that he should flee. Paul thinks he may have killed him, but he doesn't remember anything. Margo appears, and apologizes for following Peggy. Peggy tells her that she's going to help Paul escape. Margo replies that running won't help, and Paul agrees with her. Peggy reveals how Paul's uncle had tried to turn her against Paul, but she staunchly remained faithful to him. Marty bursts in on the reunion and tells them that he has called Weston and made a deal: his reduced sentence for Paul. His version of the story was that Paul wanted to escape and he tried to stop him, so he went after him to bring him back. Peggy attempts to stop Marty with a gun, but it doesn't work, and Marty manages to disarm her. Suddenly, The Shadow's voice is heard. To everyone's amazement, especially Margo's, he commends Marty on his "good deed" and asks him to come to the house to get his reward.

Weston is at the house waiting for them when they arrive. Peggy begs Paul to profess his innocence, but Paul doesn't see the point anymore. Weston tells The Shadow that this is an open and shut case, and The Shadow agrees — except that the wrong person is being arrested. Weston argues that there were witnesses. The Shadow switches on the recording machine and plays back the argument that everyone heard before they found the uncle dead. Upon hearing it, Edwin demands that he turn it off. The recording machine was attached to a hidden speaker in the wall to frame Paul. It was Edwin who had killed the uncle and was working with Marty to pull it off. Marty decides to make a run for it but is shot and wounded by Weston. He will live to pay for his crime.

It is some time later, and Lamont visits Margo in her apartment to tell her the good news: Edwin has confessed to his crimes, including the embezzlement that Paul was framed for, Marty confessed to killing the prison guard, Paul is to be freed soon, and Peggy had never looked happier. Margo then asks Lamont to tie up some loose ends about the case. It turns out that Paul wasn't in the house at the time of the murder. When Marty knocked him unconscious, he had a temporary loss of memory, and was in the cave the whole time as Edwin and Marty built up a case against him. Marty hoped to gain a parole for catching a "murderer", and Edwin convinced him to get Paul to escape so they can pin the murder on him.

Lamont has his own philosophy: "no matter how cunningly planned or brilliantly executed, murder has a way of pointing to the guilty one, and demanding payment!"