Detective Clancy Higgins joins his partner, Wylie Wong, and Captain Olderman in the hotel room of the third “Missing Heart Murders” victim. Mrs. Swan, in the room across the hall, witnessed a man leaving the murder scene. When Higgins and Wong interview her, they discover hotel resident Duke Southwick hiding in her closet. Mrs. Swan admits the fleeing man dropped his suitcase and Duke took it before the police arrived. Higgins and Wong retrieve the suitcase, noting it is new. Meanwhile, at a hospital, Dianne and Leigh Gregory consult with Dr. Norton Williams, who informs them that Dianne requires a heart transplant. Dianne’s prognosis is excellent if they find a heart with the correct tissue match, but Williams admits that finding a donor is difficult. As they arrive at the natural history museum, Higgins and Wong debate the relative effectiveness of guns versus ancient darts with curare poisoned tips. They ask the museum’s anthropologist about cannibalism, including the consumption of hearts, and learn it is rare, except among remote tribes in Borneo. Before leaving, Higgins borrows a dart from the museum’s exhibit to test if the curare is still effective. At lunch, Higgins and Wong review the evidence, noting the victims had needle and knife marks, anesthetic in their systems and hearts neatly removed; and at the last murder, the hotel clerk claimed a man and woman rented the room, refusing help with their luggage. Higgins believe they smuggled a dead body in their luggage, but Wong disagrees and leaves, taking with him the suitcase they retrieved from Duke. He canvasses luggage shops and finds the clerk who sold the suitcase. The credit card receipt leads Wong to Fred Eaton’s home. Eaton sees Wong sneaking into his garage and shoots, but Wong dives out of the way. When police surround their home, Eaton professes innocence to his wife, Antoinette, and she convinces him to surrender before their children return from school. At the police station, Eaton admits he went to the hotel room with his mistress, saw the dead body and ran away, not calling the police for fear his wife would learn of the affair. When Higgins revisits the murder scene, the officer guarding the room says he met the victim prior to her death, when she had been the victim of a mugging. That night, Leigh receives a telephone call from someone who offers to acquire a heart for Dianne. The next morning, Dianne asks Dr. Williams if there are priority lists for patients who can afford to pay, but Williams insists there are no such lists. Later, Higgins realizes there could be a black market for organs and questions Dr. Williams, who denies it and claims the transplant process is too complex. As Higgins leaves the hospital, he witnesses a reunion between Richie Walker and Harvey Nichols, two former military medical personnel in Vietnam. Nichols is an ambulance driver and owns the Allied Ambulance company. Walker is a medical resident, but confides he has a lucrative side business, then drives off in a red Cadillac convertible. Meanwhile, Leigh wants to contact the police about the donor heart offer, but Dianne feels it is her only chance to live. When Leigh arrives at the building, the contact conducts their deal via the entryway intercom and orders Leigh to place $200 thousand in an escrow account at a Swiss bank. After Dianne’s operation, the money will transfer to the contact’s account. The next morning, at the police station, a lab technician returns the curare dart, informing Higgins the poison is still lethal. That night, a masked intruder breaks into a medical records room to copy pages from Tom Moore’s file. When a security guard arrives, the intruder kills him, then runs into the next room and steals bottles of pills and blank prescription pads. Outside, a junkie watches as the intruder dumps the stolen items into the trash and leaves in a red Cadillac, then the junkie retrieves the loot. At the crime scene, Wong surmises that a junkie stole the drugs but Higgins, wondering why an addict would enter the records room, discovers a page from Moore’s file left on the copy machine. Meanwhile, the junkie attempts to fill a fake prescription and the pharmacist alerts the police. Higgins and Wong question the junkie and learn about the red car. Higgins remembers Walker’s Cadillac, but when Higgins and Wong investigate, they learn Walker is an undercover narcotics officer. Later, when the Captain warns that there is pressure from the Mayor to drop the black market angle, Higgins confronts Dr. Williams and threatens to arrest him for murder. The doctor apologizes, claiming he was worried about bad publicity for the transplant program. Dr. Williams provides a pager for Higgins so he will be aware of any transplant operation. Later, while Higgins and his girlfriend, Tiffany, share a picnic, the pager goes off. Across town, an Allied Ambulance picks up a male victim, but when they arrive at the hospital, a woman is on the gurney. Dr. Williams informs Higgins that a drug overdose victim is the donor and the detective attends the transplant operation. That evening, police discover another “missing heart murder” victim and Higgins is stunned to see she is the “drug overdose victim” from the transplant surgery. Higgins and the deputy coroner go to the drug overdose victim’s funeral, open the casket and discover an intact male body in the coffin. Higgins realizes the bodies were switched and questions Nichols, who admits he thought the pick-up was for a male, but there was a woman in the room, so he assumed he was mistaken. As Higgins leaves his business card for Nichols, he accidentally leaves his wallet behind. Higgins and Wong discover that the previous victims were mugged prior to their murders, and surmise the killer obtained blood samples for tissue matching. Higgins learns that Tom Moore was mugged and visits him in the hospital, warning that Moore is the next victim. Dr. Williams provides a list of patients who match Moore’s tissue, including Dianne. The Gregorys admit their complicity and provide their organ contact’s address. The police decide to use Moore as bait and assign two officers to watch him, but Tom Moore is kidnapped at a grocery store. Later, Higgins cannot find his wallet and returns to Allied Ambulance. Harvey’s partner, Jamie, stalls Higgins outside while Nichols secures an unconscious Moore in a secret cavity beneath the gurney’s mattress. Nichols denies having the wallet, but shows it to Jamie after Higgins leaves. At the police station, Higgins realizes the killers will not murder Moore until they have another body to substitute and decides to create a trap by staging an accident. Nichols and Jamie arrive at the “crash” and are surprised to find Higgins is the “victim.” Nichols is arrested, but Jamie runs into an adjacent bus yard and Higgins chases him. Higgins is shot in the hand and loses his gun, but he has the curare tipped dart in his pocket. Higgins climbs onto a bus, jumps Jamie and jams the dart into his chest. Jamie dies and Moore is found alive.