Jack Jill

The novel opens with parallel acts of violence. In Georgetown, a man calling himself Sam Harrison enters Senator Daniel Fitzpatrick's apartment, where an ash-blond woman greets him. She whispers "Jack," and he responds "Jill," establishing them as a coordinated killer duo. They handcuff the senator to his bed, film his last moments, and Jack shoots him execution-style, leaving a mocking rhyming note. Across Washington in Garfield Park, a separate killer disguised as a homeless man lures a young Black girl with colorful balloons and beats her to death.

Alex Cross, a D.C. deputy chief of detectives and psychologist, is woken by his partner and lifelong friend, Detective John Sampson. The victim, six-year-old Shanelle Green, has been found at the Sojourner Truth Elementary School, four blocks from Cross's house and the school his son Damon attends. A local informant leads them to Emmanuel Perez, a rumored child molester who dies falling between rooftops during a chase. Child pornography in his apartment seems to close the case, but the real killer gloats from afar that the police caught the wrong man.

Cross returns home to Nana Mama, his eighty-one-year-old grandmother who raised him and helps care for Damon and his daughter Jannie. His superiors order him onto the Jack and Jill investigation at the FBI's request, overruling his protests. When a second child, seven-year-old Vernon Wheatley, is found murdered with the same injury pattern, Cross confirms a serial killer is at work and secretly assembles an off-the-books detective unit to pursue the child case on their own time.

Jack and Jill execute TV newswoman Natalie Sheehan in her Jefferson Hotel suite, leaving another rhyming note. Cross builds a profile: The killers are likely white, persuasive, and highly organized. He physically confronts Chief of Detectives George Pittman after Pittman pushes him during a dispute, an act he knows may end his career. The killers escalate by sending CNN a video manifesto and executing actor Michael Robinson at the Willard Hotel.

Cross is summoned to the White House, where a crisis team includes Secret Service agent Jay Grayer, Chief of Staff Don Hamerman, and CIA Inspector General Jeanne Sterling. Hamerman reveals that "Jack and Jill" is also the Secret Service code name for President Thomas Byrnes and the First Lady, and that the killers have been calling the Secret Service after each murder, claiming they are "practicing for the big one." Cross meets the President, who pledges full cooperation. At CIA headquarters, Sterling reveals the Agency suspects one of its former contract killers may be Jack, drawn from a freelance list of sanctioned assassins called "ghosts." Cross and Sterling identify photojournalist Kevin Hawkins, a former CIA assassin with extreme right-wing ties, as the prime suspect.

The child case develops in parallel. Cross visits the Sojourner Truth School and meets its principal, Christine Johnson, a sharp woman married to a lawyer named George. Cross finds himself drawn to her. A street informant provides the first real lead: Someone saw an old, white, homeless man near the murder scene.

Jack and Jill grow bolder. Jack murders General Aiden Cornwall, a crisis team member, at his Virginia home and shoots Cornwall's nine-year-old son when the boy witnesses the killing. Hawkins assassinates a Japanese corporate chairman in San Francisco as a final rehearsal. At the Kennedy Center, Hawkins kills Charlotte Kinsey, a young law student revealed to be President Byrnes's mistress; a note warns the President directly. Jill then calls Byrnes on a private White House line, bypassing all security, telling him his "assassination is already a done deal." Cross and Sterling attempt to apprehend Hawkins, but he escapes after a chaotic chase.

The Sojourner Truth case turns when the Prodigy interactive network, an early online service, alerts Sampson that a subscriber has been posting accurate details about the child murders. The account traces to the household of Colonel Franklin Moore, and suspicion falls on his thirteen-year-old son Sumner. Cross and Sampson raid the home but find it empty, with Shanelle Green's bloodstained blouse left behind. When Sumner's body is later found murdered in the same pattern, Cross realizes the real killer framed him. The true culprit is Danny Boudreaux, a thirteen-year-old classmate who has stopped taking Depakote, a prescribed mood-disorder medication. Boudreaux murders his foster parents and disappears.

President Byrnes decides to resume his normal schedule and travel to New York for a speech at Madison Square Garden. The narrative reveals that Sara Rosen, a White House staffer for nine years, is Jill, having served as Jack's eyes and ears in the administration. On the morning of the speech, Sam and Sara meet at the Peninsula Hotel. After a final intimate encounter, Sam shoots Sara with a silenced pistol and places a poem in her hand. He drives toward Washington, calling his wife and daughter, considering himself a patriot.

At Madison Square Garden, Kevin Hawkins, disguised as a female FBI agent, detonates a concussion bomb near the stage, forcing the Secret Service to evacuate Byrnes through a predetermined escape tunnel. Hawkins is waiting inside and fires five shots. Cross, who had been urging a route change, arrives to find the President bleeding on the floor.

Days later, Cross searches Sara Rosen's apartment and finds an unmarked tape inside a cassette box for Hitchcock's Notorious. The uncut footage of Fitzpatrick's murder clearly shows the killer's face: not Kevin Hawkins. The real Jack is Brett Sterling, a decorated former Army colonel and husband of Jeanne Sterling. Cross and Grayer arrest Brett at a suburban stoplight. At the Sterling house, Jeanne declares they acted as patriots to stop a "foolish amateur" president from dismantling American intelligence. She shoots Grayer through her robe pocket and flees to the garage, using her three-year-old daughter as a shield. Cross pursues and subdues her.

While Cross is in New York, Danny Boudreaux, fixated on Cross as a father figure who rejected him, goes to Christine Johnson's house to draw Cross in. He shoots George Johnson dead and holds Christine at gunpoint. Cross flies back and enters the house at the boy's demand. He positions himself and Christine on opposite sides of the room so Boudreaux cannot target both. When the boy fires at Christine, Cross tackles him and wrenches the gun free. Boudreaux experiences a grand mal seizure and whispers, "I'm afraid. I don't know where I am." Cross acknowledges he understands, a recognition that disturbs him.

President Byrnes dies from his wounds, and Vice President Edward Mahoney is sworn in. Both Sterlings are found dead in their cells at Lorton Prison, apparently poisoned; evidence suggests Jeanne fought her killer. Their deaths prevent the larger conspiracy from being exposed. Cross draws parallels to the Kennedy assassination, concluding there are "too many logical suspects." The full truth may never be known.

Cross is suspended for his confrontation with Pittman and returns home. Christine arrives at his door one night, and he brings her inside. On Christmas Eve, as Cross decorates the tree with his children, Gary Soneji, a kidnapper from Cross's past who has escaped prison, calls to reveal he left the family cat at the household months ago, meaning he has been watching them. Cross hangs up and returns to the Christmas tree, carrying the knowledge that the monsters are never truly gone.