Detectives Joe Kirby and Lexi Taylor recount their time tracking a chilling killer known as Mr. Shiny, who terrorized California's Inland Empire for three decades. The case opens with a disturbing trio of crimes that seem unconnected at first: in 1993, a young woman is found dismembered and left in the San Bernardino National Forest; soon after, a bedridden elderly man is bludgeoned and stabbed to death in his retirement facility; and a third victim, a young boy named Noah Lafone, is abducted and discovered murdered in a bog, his liver cruelly removed. The investigators sift through these brutal acts, tracing chilling patterns and oddities, but the link between them remains elusive at the time.
In 2013, the Sheridan family is murdered in their own home, bound at the dining room table and exsanguinated through cuts to their femoral arteries, their blood used to paint a strange symbol on the vaulted ceiling. The killer does not stop there: a young woman is killed in her residence, and Glen Sandweiss is left with his face burned by a blowtorch. Another male victim is found in an abandoned, half-filled pool surrounded by leeches and barbed wire, drowning slowly as the water rises around him. Investigators trace the killer’s online footprint to a coffee shop, where they learn he connected with victims via public Wi‑Fi; the scene introduces a homeless man who had a close encounter with the killer, who was driving a stolen van. The van’s owner, Victor Shamaz, becomes a person of interest, claiming the vehicle was taken by a masked man who assaulted him.
As the hunt continues, Kirby and Taylor locate a house Sykes has rented for a year, though it’s largely empty, and the same symbol appears above the front door, etched in blood. Meanwhile, Sykes taunts the police with letters that reference occult notions like Kaliban, hinting at hidden knowledge. The investigation reveals that, during a twenty-year absence from California, Sykes had moved to Jerusalem and traveled through the Middle East and Europe, studying ancient sites and occult practices that feed his killings.
A teenager, Victoria Macenroe, is shot in her home by Sykes, and her blood is used to draw the same symbol on her bedroom wall. She survives and is hospitalized, but Sykes infiltrates the hospital in disguise as a nurse and ends Victoria’s life by adding drain cleaner to her blood transfusion bag. The terror continues when an employee at a doughnut shop is murdered; Saroj Mallick, a security guard, encounters Sykes but cannot stop him. Mallick is later found dead, hung in a local playground and executed via the archaic ritual known as the blood eagle. In a storage unit rented by Sykes, investigators uncover a grim cache: organs from victims, occult-like books, and a statue of a leech-like creature.
Following a conversation with a rare acquaintance of Sykes, Kirby and Taylor learn that the killer claimed to have had a spiritual awakening after entering a peculiar desert cave in the early 1990s. It’s surmised that his murderous spree has been orchestrated to culminate during a rare planetary alignment that occurs only every 800 years. The violence intensifies when Sykes murders a young couple and abducts their infant son. The trail leads to the San Bernardino National Forest, where Kirby and Taylor confront him as he attempts to burn the child alive on a ritual pyre during the celestial event; they shoot him dead to stop the mutilation. The night’s events are marked by a strange light in the sky that witnesses cannot explain.
Kirby and Taylor reflect on the case, choosing not to attribute any supernatural or cosmic cause to the killings, even as a postscript in the form of a letter hints at a return in 800 years to continue the mission. In a post-credits scene, Kirby is seen in footage from his cell phone, continuing to search for the cave where Sykes claimed to have had his supernatural experience.
