Devoted

Three years after her husband Jason's death in a helicopter crash, Megan Bookman lives outside Pinehaven, California, with her 11-year-old son, Woody. Woody has never spoken a word. Diagnosed with a rare form of autism, he is a prodigious autodidact who taught himself to read at four and reads at a college level by seven, but he finds strangers frightening and communicates only through gestures. When overwhelmed, he retreats psychologically into "Castle Wyvern," an imagined medieval fortress where he performs penance until a sign releases him. Megan loves him fiercely, and their bond sustains them both.

Woody is also a skilled computer hacker who has spent over a year investigating his father's death. By infiltrating the systems of Parable, Inc., the tech conglomerate founded by multibillionaire Dorian Purcell, Woody discovered that Purcell uses a hidden identity, "Alexander Gordius," to access a Dark Web murder-for-hire site called Tragedy. The site's video montage includes footage of Jason's helicopter crash among dozens of staged deaths. Woody has compiled 104 pages of evidence, but when he revisits the Tragedy site, its security system detects him and displays a threatening message: "WE WILL FIND YOU" (73). Terrified, he unplugs his computer and curls into a fetal position.

At a house above Lake Tahoe, a golden retriever named Kipp lies beside his dying owner, Dorothy Hummel. Kipp is a member of the Mysterium, a community of roughly 86 dogs, mostly golden retrievers and Labradors, whose intelligence has been enhanced to a human level through unknown genetic engineering. They communicate telepathically via a psychic medium they call "the Wire." Dorothy devised a system using a pedal-operated laser pointer and a painted alphabet so she and Kipp could converse. After Dorothy dies, Kipp sets out on foot, drawn west by a strange murmuring on the Wire that he suspects comes from a human boy, something no Mysterian has ever encountered.

Far away, Lee Shacket, the 34-year-old CEO of Refine, a subsidiary of Purcell's empire, flees Utah after a catastrophic breach at Refine's research facility near Springville. Scientists there used programmed archaea, microscopic organisms capable of transferring genetic material between species, for longevity research; a fail-safe incinerated the building, killing 92 employees. Shacket escaped moments before lockdown but is contaminated with the archaea, which are rewriting his DNA. He calls the process his "becoming": his senses sharpen, his strength surges beyond human limits, and his moral restraints dissolve. Fixating on Megan, whom he briefly dated 14 years earlier, he calls her from a motel and proposes she join him in Costa Rica. She declines, which enrages him.

Shacket's violence escalates rapidly. On a California highway, he murders a couple, Painton Spader and Justine Klineman, the latter by biting her repeatedly and consuming parts of her face. He infiltrates the Bookman house, hides for hours, empties Megan's pistol, and after she retires for the night, enters Woody's room. He wakes the sleeping boy and taunts him, his eyes glowing with eerie phosphorescence.

Megan discovers the empty magazine, reloads with spare ammunition, and finds Shacket threatening to gouge out Woody's eyes. She fires, tearing off part of his ear. Moving with inhuman speed, Shacket snatches Woody and escapes through a bathroom window, dropping 15 feet and landing on all fours. He re-enters by smashing a sidelight window, but approaching sirens force him to flee. Deputies arrive, and Megan barricades herself with Woody, who has retreated deep into Castle Wyvern.

Kipp, still traveling toward Woody's signal, is rescued from a violent campground manager by Ben Hawkins, a former Navy SEAL turned novelist, who recognizes Kipp's extraordinary intelligence. That night, Kipp wakes Ben urgently: The boy on the Wire is screaming in terror. Ben drives through the night, following Kipp's directional cues.

Carson Conroy, the county medical examiner, autopsies Spader and Klineman and discovers human bite marks. Men from the state attorney general's office seize the bodies, claiming national security. Sheriff Hayden Eckman, a corrupt politician, cooperates without resistance. Carson independently identifies the killer as Lee Shacket and begins investigating the connection to Purcell. Shacket is captured after a violent struggle but escapes the county hospital, killing a deputy and a maintenance worker.

Kipp arrives at the Bookman house, races past deputies, and bounds onto Woody's bed. Boy and dog lock eyes and share their entire lives telepathically through the Wire. Woody speaks his first words aloud: "No. His name is Kipp" (223). He tells his mother about Dorothy, declares his love, and begins speaking freely. Rosa Leon, Dorothy's former hospice nurse and now Kipp's legal guardian, arrives having tracked Kipp's GPS collar. Carson comes to warn that Shacket has escaped. Ben recognizes that Rosa is protecting Kipp's secret.

Through the Wire, Kipp connects Woody to the Mysterium's broader world. Bella, a yellow Labrador in Santa Rosa who serves as the Wire's editor, reports that new communities of enhanced dogs, including German shepherds and Bernese mountain dogs, are making contact across the western United States; the Mysterium is growing rapidly. Bella teaches Woody to fully use his telepathic abilities, further unlocking his cognitive potential. During this time, Woody takes his mother's hands and sends her a telepathic message of love so powerful that Megan instinctively returns her own, opening a two-way connection that leaves both weeping with joy.

The group faces threats from multiple directions. Ben argues they cannot run because Purcell can find them anywhere. Rosa contacts Dorothy's attorney to safeguard Woody's report. Meanwhile, Purcell pressures Attorney General Tio Barbizon to withdraw all deputies from the Bookman property. Eckman is subsequently murdered by his lover and undersheriff, Rita Carrickton, who stages his death as a suicide. Purcell's longtime partner, Haskell Ludlow, eliminates the Tragedy operation and dispatches four killers from Atropos & Company, a rival Dark Web assassination outfit, to capture Megan and Woody alive. Before dawn, Kipp and Woody summon dozens of Mysterian dogs and their human companions from across California and Oregon. Carson stages the visitors' vehicles at an abandoned trailer park, and the group assembles secretly at the house.

When the Atropos team arrives disguised as FBI agents, Ben plays the welcoming host. The killers enter the living room, where the household sits over coffee as if at afternoon tea. Woody signals on the Wire. Kipp howls from upstairs, and scores of Mysterian dogs thunder down the stairs, followed by dozens of armed human companions. The dogs overwhelm the killers; Ben disarms the one who grabs Woody. Under truth serum, one operative reveals everything about Atropos, the Gordius identity, and the plan. Megan records the confession and sends it to the attorney. Ben releases the prisoners, trusting their violent natures to resolve the problem. The four killers turn on one another, and all die when one triggers an explosive device they had rigged at a nearby house.

Shacket, now grotesquely transformed, infiltrates Purcell's mansion in Tiburon. He kills and partially cannibalizes the billionaire, then collapses in the library, cocooned in gray filaments, dying from the genetic chaos consuming him.

At the Bookman house, Woody transmits the gift of telepathy to every human companion present, using the technique Bella taught him. Ben argues that the Mysterium must be revealed to the world slowly, over years, to avoid fear and backlash. In the months that follow, Ben and Megan marry. Rosa and Carson begin dating. New Mysterian communities announce themselves from across the continent. Purcell's fortune compensates the families of his victims. Ludlow is arrested in the South of France. Kipp finds a mate, a golden retriever named Velvet, and they produce a litter of eight. Woody learns to play piano, speaks freely, and remains the sole human capable of opening the Wire in others, a translator between species whose ancient bond now points toward a future that will transform the world.