On Sunday morning, Agent Chambers wakes feeling better about his decision to distance himself from Pendergast. As he prepares coffee, the phone rings. Dr. Magnus informs Chambers that his mentor, Dr. Telligren, was murdered rather than dying of natural causes. Magnus claims that Telligren’s heart attack was deliberately induced and that Agent Pendergast is coming to question him that afternoon. Magnus requests Chambers’s presence at the two o’clock meeting on the Fantôme, stating that Pendergast has been intimidating and hostile toward him and that he would feel safer with Chambers there. Chambers agrees, concerned that Pendergast’s erratic behavior might jeopardize the case.

Shortly before two, Chambers arrives at the Port and observes the Fantôme, an opulent three-decked paddle wheel steamboat with smoke issuing from its twin stacks. Pendergast arrives and correctly guesses that Magnus called Chambers. They agree that Pendergast will lead the questioning; he warns that Magnus intends to toy with them.

Two crew members escort them through the saloon to Magnus’s stern cabin. Magnus, in a captain’s uniform, greets them warmly. Chambers starts a tape recorder and turns the questioning over to Pendergast.

Pendergast asks Magnus for his theory on Telligren’s death. Magnus describes an unnamed suspect who removed evidence from the crime scene, harbored antipathy toward Telligren, and directly threatened him. He accuses Pendergast of the murder, revealing his knowledge of Pendergast’s family history of mental illness, a poisoner great-aunt, and a criminal brother. Pendergast reminds Chambers that he warned him that Magnus would likely taunt them.

Magnus views the confrontation as a fencing match, glancing at a brass clock and anticipating his decisive attack. He distracts them by describing mementos, including a Guarneri violin and the scalpel from his first operation. Pendergast’s hand shifts toward his holstered weapon. When Pendergast tells Chambers that they must leave, Magnus formally requests that Chambers arrest his partner for murder.

Magnus senses Chambers’s growing physical distress and confesses that he is the one who visited Telligren, administered the drug, and murdered him. Chambers cries out, clutches his chest, and collapses. In that moment, Magnus disarms Pendergast. Three crew members enter with assault rifles. Magnus reveals that he poisoned Chambers’s morning coffee with a fatal nerve agent timed to trigger the seizure. He taunts the dying Chambers, who expires. Magnus orders Pendergast locked in a secure hold and Chambers’s body thrown overboard once they reach deep water. The Fantôme begins to move.

Pendergast sits motionless in absolute darkness within a riveted steel coal bunker, ankle-deep in coal dust. Staggered by Chambers’s cruel death, he resolves to avenge his partner. He analyzes Magnus’s extrasensory ability, concluding that it is short-range and cannot penetrate walls or barriers. He recalls a photograph from Magnus’s study showing Telligren with three graduate assistants: Magnus, Wickman, and a third student who died by suicide. This confirms his theory about the PSI laboratory experiments that gave Magnus his telepathic powers while driving the others to mental illness.

He invokes his Ghost Company creed of loyalty unto death. A childhood memory of his brother Diogenes, who secretly rigged a model steamboat with explosives and detonated it during its maiden voyage, killing their neighbor’s dog, reminds Pendergast of his intimate knowledge of paddle steamer construction.

He deduces that he is in the boat’s original coal bunker. A search reveals a broken steel strongback and a sealed hatch. Using twisted metal as a pry bar, he opens the coal-loading port onto rushing water. After blackening his skin with coal dust for camouflage, he climbs through the port and emerges onto the deserted cargo deck.

As evening descends, Magnus stands in the pilothouse with Captain LaGrange and Mako John, Magnus’s “right-hand man.” The Fantôme passes Venice, Louisiana, and enters the wilderness of the Mississippi Delta.

Magnus reflects on his PSI powers, which extend only 15 or 20 feet and cannot penetrate barriers. He considers this gift a curse, forcing him to perceive the tedious, banal thoughts of others: “Before his awakening, he had had no idea how tedious the average human being was; how almost no one expressed a glimmer of intelligence or original thinking” (316). He considers Pendergast an exception: a man with a mind that rivals his own powers. The Fantôme continues toward Goose Island Outside Pond.

Pendergast hides in a recessed hatchway on the cargo deck. Seeing it clear, he slips into an unlocked storeroom. He takes a sharp deburring implement with a swiveled hook, a six-inch steel marlin spike concealed up his sleeve, and gathers rope, a signal flare, gaffer tape, a can of acetone, and a pressurized cartridge of halon fire-suppression gas in a haversack.

He resolves to kill everyone aboard, channeling the “pitiless violence” of his Ghost Company days to avenge Chambers. Hearing a single person approach, he ambushes the man, killing him with the marlin spike. His pocket watch is destroyed in the struggle. After taking the dead man’s handgun, he hides the body. Covered in coal dust and blood, he reflects that he must look monstrous—and thinks that this is fitting.

Magnus exits the pilothouse and settles in the saloon. He reflects on his research into Pendergast’s background—the entire family comprises criminals and murderers going back generations. His brother, Diogenes, appears particularly dangerous. Magnus worries that his PSI powers might be waning and plans to interrogate Pendergast thoroughly before killing him.

Pendergast enters the crew mess and surprises a 15-year-old cabin boy clearing the table. Seizing the terrified youth, he interrogates him. The boy lists the eight crew members: Magnus, Captain LaGrange, Mako John, chief engineer Robertson, engineer’s mate Dunning, and three crewmen named Manning, Rodney, and Goins. Their destination is Goose Island Outside Pond. No one except Magnus is allowed behind a mysterious steel door.

Pendergast spares the boy’s life. He takes him to the railing and heaves him overboard, ordering him to swim to the nearby shore. Pendergast watches the boy reach the muddy embankment.

Pendergast picks the sophisticated lock on the mysterious steel door. Inside is an opulent bedroom with a brocaded bed, an Aubusson carpet, and paintings. Beside the bed stands a stainless-steel morgue gurney surrounded by racks of formalin, ethanol, embalming needles, forceps, and trocars. The bed is “turned down invitingly, as if perhaps awaiting a tryst” (328). Pendergast concludes that this room expresses the variety of mental illness that Magnus developed as a side effect of the PSI experiments.

He relocks the door and proceeds to the engine room. He kills Robertson with the marlin spike and captures Dunning, tying him to a pipe but deliberately allowing him to keep his radio. He jams the halon gas cylinder into the speaking tube connecting to the pilothouse, releasing gas to asphyxiate the occupants. He takes Robertson’s weapon.

Pendergast forces Dunning into the main cargo hold and ties him to cargo braces, leaving his hands free. He punctures the acetone can. He hears Dunning whisper into his radio and pretends not to notice. Moments later, a ship-wide alarm sounds. Three men with assault rifles burst into the hold. Pendergast sprints up a metal staircase, returning fire, ignites a flare in the acetone pool, and dives through a door as a massive explosion shakes the ship. Only Magnus remains alive.

Magnus is in the saloon when he hears Dunning’s whispered radio call for help. He orders Mako John, Rodney, and Goins to the cargo hold to kill Pendergast and activates the emergency alarm. He tries to raise the engine room and helm on the radio but receives no response. The acetone explosion occurs, violently shaking the boat. The Fantôme lurches to one side and begins to spin.

Magnus sprints to the cargo deck and sees fire inside the cargo hold. He enters the engine room and finds Robertson dead in a pool of blood. Pendergast calls Magnus on the radio from the saloon, taunting him by saying that he is rinsing blood from his hands with Magnus’s expensive cognac and that the rest of the crew are gone.

A second explosion rocks the cargo hold as smoke fills the engine room. Magnus realizes that the boat is on fire and sinking by the bow. Accepting that this is a fight to the death, he retrieves an assault rifle with a 100-round drum magazine from a hidden gun locker. He exits onto the slanting deck and runs to the grand staircase, where he sees Pendergast at the top. They exchange gunfire, and Pendergast disappears out the saloon’s aft exit.

Magnus chases him, getting a faint mental echo that encourages him. The fire spreads to the stateroom deck. Pendergast leaps from a window and dashes up a ladderway to the hurricane deck. Magnus follows, gaining a stronger mental read. He learns that Pendergast’s pistol holds only 10 rounds and that he has already fired six. To flush him out, Magnus deliberately exposes himself, using his mind-reading ability to dodge Pendergast’s ninth and then final shot.

Magnus confirms that Pendergast is out of ammunition, his only weapons a marlin spike and a sharp tool. He walks openly toward the longboat where Pendergast is hiding and deftly dodges the thrown spike. He orders the unarmed Pendergast to emerge. Pendergast steps out, covered in coal dust and blood. Magnus asks if Pendergast has “the gift.” Pendergast says that he is merely observant.

What he means by this becomes clear as something grabs Magnus from behind. He fires wildly as he is lifted into the air and thrown over the railing toward the churning paddle wheel.

Pendergast watches Magnus’s body wedge in the paddle wheel, carried down into the water and brought back up mangled and bloody. On the next revolution, the wheel comes up empty. An explosion knocks Pendergast off balance. He retrieves the handgun and dives overboard, swimming to shore and watching the Fantôme’s fuel tanks explode in a massive fireball.

A horribly injured Magnus emerges from the tall grass. He asks how Pendergast tricked him. Pendergast explains that he used a Tibetan mental discipline to project a false visualization while physically positioning himself behind Magnus.

Magnus expresses gratitude to Pendergast for enlivening his “dull” life and mentions his secret, a “fragrant jewel” in the cellar of his house. He asks if Pendergast’s gun was truly empty. Pendergast ejects the final live round, shows it, reinserts it, and offers Magnus the gun. Magnus takes it, tucks it under his chin, and pulls the trigger.

The next day, a disguised Pendergast observes Magnus’s Garden District mansion from across the street. The mansion swarms with NOPD and FBI agents. He has been excluded from the official investigation, but Pendergast doubts the investigators will find Magnus’s secret room.

He enters through a broken window in the exercise room and searches the basement. He discovers a section of interior brickwork where the moisture crust has been faked with paint. He finds the hidden release by pulling a specific book, Canon Medicinae Avicennae, from a nearby bookcase.

Inside is an elegant bedroom almost identical to the one on the Fantôme, with embalming equipment and a cryogenic chamber. A dead and severely decayed woman lies in the bed, showing extensive preservation efforts. Pendergast pulls back the coverlet and sees that the body has been repeatedly violated over a long period. Horrified, he grabs a sheaf of letters, goes upstairs, finds Estevez, and tells him that he must go to the basement.

Seventy-two hours later, the Magnus case has become a massive scandal: one senior agent poisoned, New Orleans’s most respected doctor exposed as a murderer and “deviant,” the Fantôme destroyed, nine corpses recovered from the Delta, and a young socialite’s body discovered in Magnus’s house. Pendergast asks if the plaque for Chambers on the Wall of Heroes has been approved. Estevez confirms the recommendation. He informs Pendergast that he has recommended him for full agent status when his probationary period expires in six months, but with reassignment to a new field office outside Louisiana. Estevez places Pendergast on desk duty, suggesting cold cases. Pendergast mentions interest in a six-year-old case involving a freighter in Bayou Grove.

Pendergast visits Proctor in the hospital. Proctor is reading a Trollope novel. Pendergast recounts the full story of Wickman, the PSI experiments, and Magnus. He clarifies that Agent Chambers saved Proctor’s life and informs Proctor that his old courier job went off without incident, though his two colleagues were indeed conspiring together.

Proctor says that he has no desire to return to his old team. He explains that after Ghost Company operations, conventional life feels unsatisfying. Pendergast tells Proctor that he needs a driver for his Rolls-Royce Silver Wraith but clarifies that it will be far more than a chauffeur role; it will require Proctor’s “very special skills” (358). Proctor accepts with a faint smile.

Seven months later, Lieutenant D’Agosta arrives at a gruesome murder scene in the New York Museum of Natural History. A museum guard, Fred Jolley, lies decapitated at the bottom of a dim stairway. D’Agosta berates the responding guard for contaminating the crime scene. A tall, slender man in a black suit introduces himself as Pendergast, recently transferred from the New Orleans Field Office. When the lights reveal the full horror, D’Agosta vomits. The coroner’s investigator begins work while Pendergast points out interesting blood spatter.

In a temporary command post, Pendergast explains that the murder’s unique method—skull opened, brain removed—matches unsolved New Orleans killings from several years ago. He announces that he will be in charge but offers to work collaboratively with D’Agosta.

They return to the crime scene with the museum’s security director, Ippolito. Pendergast deduces that Jolley came to the isolated courtyard to smoke marijuana, pointing out the discarded joint. He notices a large metal door under the stairwell leading to the museum’s Secure Area. Fresh blood smeared on a Fremont Ellis mural in the hallway confirms that the killer went that way. At the door to the Secure Area, they find fresh dents and deep gouges near the bottom, as if from claws. D’Agosta and Pendergast agree to work together.