Plot

Barry Conrad has become a major star with an oversized ego. At the last moment, he tells his producer, Jackson Sidemark, that he won't be signing a new contract. Conrad, then Sidemark, are killed giving Perry two clients back-to-back.

Producer Jackson Sidemark has a hit TV series. Unfortunately, his star, Barry Conrad, tells him he won't be doing another season after Sidemark is already on the hook for numerous contractual obligations. Conrad stabs others in the back too, like the former star Winifred Glover who gave him his start, and the writer of Sidemark's show. There's little surprise when Conrad's murder occurs but nothing goes as expected after that. Conrad was killed in the midst of a scene with a last minute plot change in which guns are substituted for knives. There's perjury, dismissal of charges against Sidemark, and accusations from Burger of Perry's misconduct. After a second murder with Sidemark as the victim, Perry has a new client - the actress Winifred Glover, and must solve both cases to get at the truth. He's helped and hindered by a cast of both familiar TV faces and members of the "Perry Mason" crew in bit parts, plus Perry's creator Erle Stanley Gardner as the final Judge.—Arthur Bullock

In a boxcar on a moving train, two hobos approach a younger man from the rear, and one pulls a knife. A young woman in the car shouts "Look out!" and a fight ensues. The three combatants fall out of the car, and the woman jumps after them. A director shouts "Cut!" We're on the set of a TV series starring Barry Conrad (James Stacy), the intended victim in the scene just filmed. As preparations are started for the next setup, Barry is approached by his agent, Andy Rubin (Gerald Mohr). It's time to see producer Jack Sidemark (Denver Pyle) about his contract for next season. Barry says "I'm going to enjoy this," and leaves with Andy, ignoring the director's pleas that they are running behind schedule. On their way out, they encounter Winifred Glover (Estelle Winwood), an old-time star who discovered Barry. She thanks him for getting her a part on his show, but Barry tells Andy that he had nothing to do with casting "that washed-up old has-been."

In Jack's office, Erna Landry (Marlyn Mason), who played the woman in the boxcar scene, signs her contract for the next year of the series. Barry arrives and announces that he has a deal for a new series with himself as creator, producer, and star. Despite having given Jack his word, he won't be returning to the existing show. Jack's already on the hook for a million dollars in commitments, but Barry's only comment is "Sorry!" Jack threatens to bury him six feet under his Hollywood star, but Barry's still enjoying the moment. As they exit the office, they encounter writer Leif Early (Dick Clark) on his way in to get approval on his latest rewrites. Leif asks Barry about the status of a presentation he entrusted to the actor, and Barry says he'll let him know. Back in the office, Erna offers to tear up the contract she just signed, and Jack is grateful. Barry returns and demands that Jack fire Winifred and take the blame, otherwise the star will come down with laryngitis. Once he leaves, Jack calls Perry.

Back on the set, Leif hands out the revised scripts. The last-minute changes annoy prop master Pete Desmond (Jackie Coogan) and Barry, who has to be assured the changes don't change any dialog - just adding gunplay to the upcoming scene. As rehearsal starts, Jack enters, pulls Winifred aside, and announces that, while she'll get full pay, her part has to be recast. She's furious with him. Cameras start rolling and, once the frame line is cleared, the scene starts. The foursome tumble to earth still fighting, then police arrive and there's shooting. Once the scene is cut, Erna notices that Barry isn't getting up. He's been shot dead.

Lt. Steve Drumm interviews various people on the production (mostly played by members of the Perry Mason crew) and eventually gets to the prop man. Pete explains that due to the script change, he had to grab guns from the prop room and found he only had six to hand out to the performers. However, when he checked later, he found he had received seven guns back. The extra gun was one from the prop room that should have been there all along. Perry arrives at the studio in response to Jack's earlier call, but Steve informs him that his client is being arrested on suspicion of murder.

At the jail, Perry worries why the police have kept Pete under wraps, but Jack is confident that Pete will be truthful. Paul tells Perry that there was a still photographer on the set. Perry wants to see all those photos, in the hope that they'll help. In arraignment court, Burger has Andy and Erna testify to past confrontations between Jack and Barry. Pete repeats what he told Steve about the disappearing/reappearing gun, but this time he adds that right after the shooting, he saw Jack drop a gun into the prop box. On cross-examination, Perry produces one of the photos, showing that Jack was on the opposite side of the set from the prop box at the time when Pete just said he was dropping a gun in it. He calls Pete a perjurer. On redirect, Burger gets Pete to admit that he had to have known about the still photographer. He lamely claims he forgot or was mixed up. Asked why he didn't mention Jack dropping the gun to Steve or Burger earlier, he says he got excited and forgot. Burger accuses him of collusion with Perry to entrap the prosecution. Once the case is dismissed, Burger repeats his accusations to Perry himself, calling it a "cheap shyster trick". He vows to send Jack to the gas chamber.

Leif arrives at the studio gate and is told that Jack is in the cutting room. Perry arrives next, looking for Pete, and is directed to the prop room. He encounters Winifred, who complains about Perry getting charges against Jack dropped. She has some nasty things to say about Jack, and says she just told them to Jack personally. She promises that Jack isn't going to enjoy his freedom. Shortly after, Perry and Steve enter the cutting room. They find the Moviola running and Jack on the floor, dead. Perry meets Winifred in jail. Despite the fact that she has requested Perry to defend her, she complains that it was Perry who told the police about her squabble with Jack just before his body was found. Perry says he'll defender her because in doing so he thinks he can clear Jack, whom he still regards as a client. However, he'll only do it if she quits the tantrums and rude behavior. She finally agrees to "take direction" from Perry.

Activity still seems to be focused on Barry's murder rather than Jack's. Paul interviews Pete, who admits that he committed perjury in full knowledge that he'd be caught in a lie - thus getting charges dismissed. He says he saw something like it in a movie (a reference to Witness for the Prosecution (1957)). However, he insists that his initial story about the missing and recovered seventh gun was the truth. Paul asks who'll believe the word of a known perjurer. In the office, Paul tells Della that the still photographer is unavailable, and suggests that Perry get a court order for another print of the footage of the murder scene, so they can examine it frame-by-frame.

In court, Burger calls Winfred a "star who glitters no longer" and calls Jack's murder a "crime of temperament". Leif testifies cynically about how Hollywood works - saying that Barry gave Jack a bad deal, so Jack gave a bad deal to Winifred. Perry won't honor this diatribe with cross-examination. More members of the Perry Mason staff make cameos as witnesses testifying about Winifred's short temper. Andy testifies that Barry, not Jack, was responsible for firing Winifred, but Burger gets him to admit that Winifred couldn't have known this, so her motive still stands. The judge (Erle Stanley Gardner) adjourns the trial until 2 that afternoon.

Back on the stand, Leif testifies that he wouldn't know if there were any departures from his rewrite during filming of the fatal scene - he wasn't on the set then. With Erna on the stand, the court views the print that Perry had requested. She doesn't notice anything particularly unusual, except of course for Barry collapsing from having been shot. Perry requests that the scene be shown again - this time from the beginning. Burger says that they had watched it from the beginning, just as he and the police had done during their investigations. However, Perry points out that they used a copy with the leader (prior to the camera slate) removed. Perry's copy has that footage, and when they view it, Erna notices a briefcase, held by a someone obscured by foliage. On the call "clear the frame line" this person backs out of view, prior to the camera slate. Erna recognizes the briefcase as belonging to Leif. Perry says that Leif rewrote the scene with plenty of guns so he could shoot Barry unnoticed. His motive was that Barry stole Leif's idea for a new series and used it to get his own lucrative deal. Burger points out that they're trying Jack's murder, not Barry's. Perry counters that Jack had solved the latter case himself while in the cutting room. Therefore, Leif had to murder him too, then remove the incriminating leader of the film Jack was using. (This wouldn't be obvious, since editors routinely cut off anything before the camera slate.) Leif confesses. He's sorry he had to kill Jack, but is glad he murdered the evil Barry.

After court adjourns, Winifred is enjoying some press attention as someone acquitted of murder. Burger approaches Perry and tries to say something to him, Della, and Paul, but can't get the words out. He asks Steve to do it and leaves. It was a dinner invitation for all of them, as close as Burger can come to an apology. They accept, then begin to discuss another upcoming case. Perry's last comment is "It seems to me that the place to start is at the beginning."