Shock Treatment

Martin Ashley, a mentally ill gardener, decapitates his employer Mrs. Townsend with a pair of shears. He immediately turns himself in to the police and is found insane, resulting in his commitment to a mental institution overseen by psychiatrist Edwina Beighley. The crime sets the stage for the ensuing conspiracy around a rumored $1 million.

During Ashley's insanity hearing, Beighley learns there may be $1 million buried by the late Mrs. Townsend. This potential windfall motivates her to pursue the case, tying the money to Ashley's crime. The moment sets the stage for the plan to locate the funds.

Harley Manning, Townsend's executor, suspects Ashley and hires an actor, Dale Nelson, to fake insanity and infiltrate the same institution. Nelson's mission is to uncover the $1 million, using the job as cover to retrieve the stolen money. Manning funds the operation by placing $10,000 in a safety deposit box under Nelson's name, with the key withheld until the task is done.

To get himself inside the institution, Nelson commits a reckless act by breaking a store window and shouting against conformity, which leads to arrest. He is admitted as a patient and undergoes gardening-based occupational therapy, starting his feigned study of Ashley's world. He begins to prepare for his role and to observe Ashley.

Within the institution's gardening program, Nelson earns Ashley's trust through botanical knowledge and shared interests, including a special rose Ashley developed. He also becomes acquainted with Cynthia Albright, who slowly learns to trust him despite her issues with men. Nelson wins a gardening competition that helps solidify his cover.

During therapy, Beighley uses hypnosis on Ashley, hoping to extract where he buried the $1 million. Her desperation for funds to continue her catatonia research drives her risky method. The setup shows her willingness to cross ethical lines to secure the money.

Beighley realizes Nelson is not a genuine patient and schemes to expose him. She orders electroconvulsive therapy on him as punishment and a test of his loyalty, threatening punishment for his feigned entry. Nelson is injected with drugs that induce catatonia, setting up a life-threatening dilemma.

After a second awakening, Nelson must pretend to remain catatonic to avoid a third, permanent injection. He uses a wheelchair to maintain the illusion while plotting his next move. Cynthia visits him, and the two secretly coordinate.

During a hospital dance, Ashley wheels a supposedly catatonic Nelson outside and confronts him about betraying the trust. Cynthia signals from a distance, using a stolen key to aid Nelson's escape. With an orderly distracted, Nelson slips away and flees the hospital with Cynthia's help.

Nelson hurries to Manning's home, only to discover that Manning has died of a heart attack, and his secretary offers no information about the impersonation. The police become involved, but Nelson escapes before they arrive. He continues his plan to locate the money on his own.

Nelson arrives at the Townsend estate where Ashley and Beighley dig a hole for the buried money. They uncover a sack that contains nothing but the ashes of burnt money, shocking Beighley and proving the temptation was for nothing. Ashley becomes irate, realizing the truth and the risk.

In the ensuing confrontation, Ashley attacks Beighley as she presses for the location of the money. Dale intervenes to prevent Beighley from being harmed, and during the struggle, Ashley is impaled by a spiked fence. The estate descends into chaos as the grim consequences of the quest become clear.

Beighley's desperation drives her into a frenzied mania, convinced that the money remains hidden somewhere on the estate. Her fixation reveals her ethical collapse and pushes her toward further irrational acts. This spiral sets the stage for the sanity hearing.

Nelson testifies at Beighley's sanity hearing, swaying the proceedings, and the hearing results in Beighley's institutionalization. The revelation marks a turning point in the power dynamics at the institution. Beighley becomes a patient, leaving the medical staff in control.

Cynthia Albright is discharged from the institution and departs with Nelson, signaling an uneasy but hopeful ending. The two characters exit under uncertain circumstances, carrying the secret of the burned money. The movie closes with them stepping into an uncertain future.