Perry defends the brother of a woman who returns with a purse containing his gun, who says that in her nightmare she saw her husband shot and found the gun there. Perry must prove the nightmare was real, but why does the woman think it was a dream?
To protect his sister Helen Reed and her son, Robert Crane threatens his brother-in-law David Reed with bodily harm. The next morning Helen awakens complaining about a bad nightmare in which she saw her husband Reed dead with a bullet hole in his head. They find she returned with a purse which is not hers which contains her brother's pistol. Helen suffers from continuing nightmares that involve memories she cannot explain so she agrees to return to Dr. Maitland. Helen and her brother visit Perry to retain him to defend them in case something happened to Reed. Perry starts by looking for Mr. Reed who seems to be missing. Using the purse, they find an apartment connected to a promiscuous woman named Joyce Martel who is having an affair with Johnny Hale. Perry and Paul find David Reed murdered in Joyce Martel's apartment. Crane is charged with the crime. It is up to Perry Mason and Dr. Maitland to unravel the mystery.
- At Reed Industries, junior partner Harry Vance (Paul Langton) is heatedly defending the merits of the proposed Anderson deal to doubtful senior partner Dave Reed (Carleton G. Young) when Dave's ex-wife Helen (Constance Ford) arrives with her brother Bob Kramer (Denver Pyle) to pick up the Reeds' young son Tommy (Kelly Junge Jr.). Dave tells Bob that he wants sole custody of Tommy, and he can prove Helen is an unfit mother. Bob replies that if Dave tries anything, he'll "not live to appear in court."
That night, a somewhat drunk, fur-clad woman saunters into the Burgundy Club. She's either Helen Reed or her twin, but is known there as Joyce Martel. Johnny Hale (Murray Hamilton), the club's owner, takes her into his private office. He's unhappy that he hasn't seen her for a week, but she's in a good mood, emphasizing that she needs to be herself. She gives Johnny a playful kiss, which he returns with passion.
Later, Bob arrives at Helen's apartment, having been informed that she's sick again. She describes a nightmare in which she was wearing daring clothes and a mink, even though she's very allergic to fur. She also remembers smoking and drinking, things she never does. Worst of all, she recalls going into an apartment and seeing Dave lying on the floor with a bullet hole in his head and a gun nearby. She asks her maid Sarah (Louise Truax) to get her pills from her purse, but the purse isn't hers - it's monogrammed "J.M." and contains a gun. Helen says the purse and gun are from her nightmare.
The next day, Helen and Bob repeat their story to Perry, with one additional detail - the gun belongs to Bob. They're worried that there might be truth in Helen's dream and if so, Bob could be charged with the murder. (Because of the death threat he made in front of Harry, of course. Where does Perry get these clients?) Perry goes to Reed Industries where he's made an appointment with Dave, whose private secretary Cora Dunbar (Carole Mathews) tells him the boss hasn't come in yet. He's going to wait, but he gets a call from Della that Paul needs to see him immediately at 622 South Barry, Westwood. (Barry is a real street in the Westwood area, but it doesn't have addresses in the 600s.)
Perry arrives to find this is the Crest Apartments, and Paul has discovered that a key in the "J.M." purse is to Apartment 310, which is registered to a Joyce Martel. Using the need to return the purse to its owner as an excuse, they enter the apartment with the key and discover Dave's body. They look around a bit, and find plenty of items with the "J.M." monogram. Paul also finds a photo of "Joyce", and when he later shows it to Perry, the attorney learns that Joyce and Helen are the same person. Lt. Tragg arrives and notes that no self-respecting private eye would carry that purse with a daytime suit, so he takes it.
When Perry arrives at Helen's actual apartment, he finds a cab driver (Frank Jenks) shouting through the door that he needs to return the mink stole he's carrying to her, or he'll be in trouble. She left it in his cab last night when he drove her from her place to the Burgundy Club and later to the Crest Apartments. The allergic Helen vehemently denies the fur is hers, but the cabby recognizes Sarah from when he first picked up Helen. He knows he couldn't have mistaken two people. To Perry, this means that there's a witness to Helen having been in the area of Dave's murder around the relevant time.
Back at the law office, Bob explains that Joyce Martel was originally Helen's imaginary playmate, some of whose imaginary actions started becoming real. There's a knock on the back door Paul always uses, but it's Tragg. He announces that Bob's gun was indeed the murder weapon, and Dave was shot between 9 and 11 PM. He say's that Bob received a note from Cora saying that Dave asked him to come to Apartment 310. Sure enough, Bob has the note in his coat, but says he never read it. Just as he received it, he got the phone call that Helen was sick, and forgot about the note. Tragg is unimpressed and arrests Bob.
Paul has informed Perry about Joyce's trips to the Burgundy Club, so he goes there and barges into Johnny's private office, where he finds the club owner in the company of Helen-as-Joyce, complete with mink stole and sassy attitude. Later, Dr. Maitland (Abraham Sofaer), a psychiatrist who recently started treating Helen, explains the concept of multiple personalities. Helen perceives Joyce's actions as nightmares, but Joyce is fully aware that she and Helen inhabit the same body. Joyce's lack of a fur allergy isn't their only big difference - the doctor believes Joyce might be fully capable of committing murder.
In court, Burger is presenting his case. Sarah testifies about seeing Bob's gun in the purse. Cora explains that she sent that note to Bob on Dave's instructions. He told her that he knew of Helen's indiscretions through detectives he'd hired, and intended to prove them to Bob. If they didn't relinquish custody of Tommy, Dave planned to pillory Helen in the press. On cross-examination, Perry asks about Cora's relationship with Harry. She admits that Harry bought her a ticket for a vacation in Mexico, but she was "going to reimburse him later". She denies leaking to Harry information that Dave wanted kept from him, but in the process starts to refer him as "Harry" before correcting herself to "Mr. Vance". Harry testifies about Bob's death threat to Dave. On cross, he relates that Dave had summoned him to Apartment 310 to be a witness to his encounter with Bob, but when he arrived around 10, Dave was already there. He delayed reporting the death, and even bought Cora the ticket to Mexico, so that a check Dave had signed to seal the Anderson deal would clear.
Johnny testifies that he'd known Helen for two years, but on cross clarifies that he knew her only as Joyce. This opens up the issue of Helen's multiple personalities, despite Burger's customary sputtering about Perry's courtroom theatrics. First, Dr. Maitland explains that Helen is a "true schizophrenic". With Helen on the stand, he demonstrates her strong allergic reaction to the mink stole. Then Dr. Maitland talks to her and educes the Joyce personality. She's delighted to have her fur again, and doesn't mind admitting that she took Bob's gun, wanting to make Bob think that Helen did it. Perry accuses Joyce of the murder, but Johnny protests that he won't let her take the blame for his crime. He had a jealous rage when he saw Dave with Joyce, not realizing that they meant nothing to each other.
Later, Perry announces that Dr. Maitland holds out strong hopes for Helen's complete cure. Della thinks it's a shame that this means she'll remain allergic to fur.