Major Characters:

• The Shadow/Lamont Cranston
• Professor Gando: A scientist obsessed with a technique called "Living Surgery"
• Professor Wallace: Professor Gando's nemesis
• Bartellini: A famous trapeze performer for Romero Brothers Circus
• Mrs. Donner: Wardrobe mistress for Romero Brothers Circus
• Mr. McMannus: A staff member with Romero Brothers Circus
• Knifer Williams: A convicted knife murderer on death row

Featured Agents:

• Margo Lane
• Commissioner Weston

Minor Characters:

• Peterson (Professor Wallace's assistant)
• Newspaper Man
• Executioner
• Prison Warden Sloan

Synopsis: (Warning! Contains spoilers!)

"As the surgeon knows, the phenomenon called life is a delicate balance. To tamper with that balance is to upset it, and to upset it is to create a monster neither living or dead. A creature with no conscience, no mind of its own, but obeying the will of its bloodthirsty master. This is the story of a scientist who walked a road no mortal man dared travel..."
—The Shadow

Scientist Professor Gando addresses an audience of the Biologist Society about a peculiar practice known as "living surgery", which he has seen performed in the orient; it is the grafting of vital organs or body parts from one body to another. He is quite enthusiastic about his discoveries of this method. But one member of the audience, Professor Wallace, scoffs at his findings. He asks for proof of this "living surgery", to which Gando produces photographs. Wallace merely dismisses them as fakes and mocks him. Gando becomes angry and frustrated; it seems Wallace has been trying to ruin him for the last ten years. Gando declares that he will pay for that.

The listener now hears the newspaper man announce the news that the convicted murderer, "Knifer" Williams, is about to die in the electric chair. The scene now switches to Williams and his executioner. When asked for his last words, Williams defiantly asks for his knife. The executioner hits the switch.

Later that night, Commissioner Weston receives a most peculiar call from a prison warden named Sloan. He tells Weston that someone had snuck into the morgue and cut off Williams's hands. This is most likely the work of a skilled surgeon. Weston is shocked by the mutilation.

A week later, at Romero Brothers Circus, wardrobe mistress Mrs. Donner informs another staff member, Mr. McMannus, that Bartellini is not in his dressing room. McMannus is worried; Bartellini is famous for his triple somersault in mid air during his trapeze act, in fact people only come to the circus just to see it. Entering Bartellini's room with Mrs. Donner, they find a large wooden box on his dressing table. Curiously, the box resembles a small coffin, and comes with an unsigned note stating "Bartellini won't need these anymore". They open the box, only to make grisly discovery: Bartellini's arms, amputated at the shoulder.

One day, Lamont receives a visit from Professor Wallace. Wallace had met him several years ago in the orient while he was studying tropical diseases. Lamont's study of criminology was the reason behind the visit. Lamont modestly replies that criminology is only a hobby for him. Wallace proceeds to tell him (and Margo, who is present), about how he had systematically driven someone insane, namely Professor Gando. It seems that Gando's mind is already warped a long time ago; a brilliant mind twisted by his intense work in biological research. Wallace saw the danger in Gando's madness and in letting him continue with his diabolical experiments, mainly "living surgery". He warns that there's no telling what he might do to prove his experiments. What Wallace is trying to do is to incite Gando to attack him, so that he can have reason enough to put him safely away in an institution. Now Wallace has his wish; he has received a note about a "Frankenstein" monster, with the body of an athlete and the hands of a murderer, who is out to get him. But he isn't worried. His apartment is twenty-two stories above ground and is guarded by private detectives.

At Wallace's apartment, Margo catches a glimpse of someone on the ledge that frightens her. Then, they hear a cry from the study where Wallace's assistant, Peterson, was going over some notes. Upon arrival, they find him dead with a knife lodged in his throat. The window in the room had been opened slightly at the level of Peterson's head as he sat in his chair, enough room to throw a knife through. When Wallace goes to close the window, another knife whizzes through the opening. This time, there is a threatening note attached.

Weston arrives at the apartment to investigate. He has just finished talking to Inspector Cardona about identifying the fingerprints they've found. Margo believes that Gando was the one who tried to murder Wallace. Wallace, upon reviewing the facts in the investigation, recalls the trapeze artist, Bartellini, who went missing three weeks ago. So Gando must have succeeded in his experiments. The phone rings; it's Cardona with some surprising news: the prints found at the scene belong to none other than Knifer Williams!

Driving from the apartment, Lamont and Margo discuss the case, and Lamont decides to visit Gando as The Shadow.

Gando is in his lab when The Shadow confronts him about "living surgery" and Wallace. Gando doesn't admit to much, except revealing that he prefers to kill Wallace himself. When The Shadow tells him about Williams and Bartellini, he fails to understand his point. Suddenly, tapping is heard on the window, and Gando decides to investigates. The Shadow tries to warn him, but it is too late. Gando opens the window, only to receive a knife in his throat.

The newspaper man now announces another death by the unknown knife murderer, and the request by police for anyone with information to come forward. The scene fades to Weston giving an official statement to the press. He reports that the murderer will attempt to cover his tracks, and will murder anyone whom he believes may reveal his identity. The scene fades again to that of Mrs. Donner, of Romero Brothers Circus, reading Weston's statement in the paper. She realizes at this point who the murderer might be, and proceeds to phone the police. She tells Weston about a man who was last seen with Bartellini before his disappearance. This man always hung around Bartellini and took an unusual interest in him. As she is about to reveal the man's identity, she hears the slamming of the door and some sinister laughter. Turning to look, she finds Bartellini standing before her! "You're going to die Mrs. Donner" he tells her, before flinging a knife at her throat...

It has been four murders: Bartellini, Peterson, Gando, and now Mrs. Donner. Lamont believes the murderer will strike again with Wallace as his target. Strangely, Wallace had recently asked Weston to have the police guard removed after Gando's death. Lamont and Margo offer to search Wallace's apartment for lurkers, but they find nothing. Noticing that the fire escape hasn't been checked, he leaves Margo with Wallace. Wallace notes that Lamont is a clever man. When Lamont is gone, Wallace complements on Margo's lovely hands and asks her if she is a musician. Margo replies that she used to play the piano (note: if you've listened to "The Creeper" from the 1938-9 summer season, there is a scene near the end of the episode in which Lamont walks in on Margo as she is playing the piano. Another piece of trivia for Shadow fans!). Wallace offers to give her the business card of a piano teacher, and proceeds to his desk to find it. But instead of producing the card, he finds a carved jade bottle that he found in the orient; in it is a rare and exotic perfume. He decides to give the perfume to Margo as a gift and asks her to smell it. Margo takes a whiff of the perfume and agrees that it has a nice smell. Suddenly, the "perfume" (in actuality a hypnotic drug) takes effect and puts Margo in a trance and under Wallace's power.

Wallace pushes a button to open a secret wall panel, something Lamont and Margo failed to find while searching his apartment; within is Bartellini. Margo is commanded to send Bartellini to the fire escape to kill Lamont. Margo, though in a trance, is able to follow the first part of the instructions, but hesitates to give the order to kill. Wallace decides to do it for her. Bartellini, who is also under Wallace's hypnosis, obeys. Suddenly, The Shadow appears and confronts Wallace. It was all Wallace's plan to use "living surgery" to create the ultimate killer with the athleticism of Bartellini combined with the knife-throwing skills of Knifer Williams, and to pin everything on Gando.

Wallace isn't afraid of The Shadow; in fact, he knows of The Shadow's hypnotic methods (they met in the orient, remember?). To make matters worse, he can see through The Shadow's invisibility. He can see Lamont!

Bartellini is commanded by Wallace to take Margo to the window ledge. One wrong move from The Shadow will result in Bartellini's and her death twenty-two stories below. The Shadow tries to reach Bartellini and snap him out of his trance. He tells him that he is a man and not the knife-wielding monster that Wallace had created. He manages to convince him to rebel against Wallace and release Margo. Bartellini begins to obey and lets Margo go, but Wallace commands him to use Williams's hands to kill The Shadow. It is now a battle for Bartellini's mind.

Bartellini is beginning to wake up from his trance. He notices that his hands are different: they are strange and have a life of their own. When Wallace tells him to kill The Shadow, he looks around and finds no one. Realizing what Wallace has done to him, he uses Williams's hands not to end The Shadow's life, but Wallace's instead. But Wallace's death only serves to confuse and frighten Bartellini even more. He is horrified by his different hands, as they don't belong to him and he has no control over them. He tells himself over and over again that he really is Bartellini, the famous trapeze artist, as though he is trying to wake himself up from a nightmare. He wants to escape from it all.

In his panic and confusion, he falls over the ledge to his death...