D-Tox
Tags: mystery, murder, suicidal, horror, flashback, revenge

Plot synopsis:
FBI agent Jake Malloy is pursuing a serial killer who specializes in killing police officers. Malloy's former partner becomes one of the victims. While Malloy is at his partner's home, the murderer calls Malloy from Malloy's home while Mary, his girlfriend, is there. The killer tells Malloy that he pursued him four years before for a series of prostitute murders; he is holding a grudge and he's going to kill Mary. Malloy rushes home to find Mary dead. When the killer's hideout is found, Seattle police and the FBI blockade the area before Malloy arrives. Malloy pursues the killer only to find that he appears to have committed suicide.
Three months later, Malloy descends into alcoholism over Mary's murder. After Malloy slits his wrists in an unsuccessful suicide attempt, his best friend and supervising officer, Agent Chuck Hendricks, enrolls Malloy in a rehabilitation program designed for law enforcement officers. The clinic was formerly an abandoned military base. Dr. John "Doc" Mitchell, a former cop and recovering alcoholic, established the rehab center as a way of dealing with his problems. Hendricks stays in Wyoming to ensure Malloy will be okay.
Malloy meets several other officers who are patients in the clinic, including Peter Noah, an arrogant and paranoid ex-SWAT officer, Frank Slater, a cynical, opinionated British police officer, Willie Jones, a religious homicide detective, Jaworski, an alcoholic narcotics cop who attempted suicide, Lopez, a foul-mouthed LAPD officer, and McKenzie, an elderly member of the Royal Canadian Mounted Police who saw his partner get killed. He meets several staff members, including Doc's assistant and mechanic Hank and compassionate resident psychiatrist and nurse Jenny Munroe, with whom Malloy develops a bond.
A blizzard seals everyone in the rehab center with no outside communication. The next day, Jenny finds the body of Connor, one of the troubled patients who apparently killed himself. Jenny suspects otherwise, believing Connor would have come to her. The next morning Hank finds the body of Carl Brandon, another patient. Brandon also seems to have killed himself, but Malloy deduces otherwise.
Doc locks up the surviving patients while he reviews their files. Jenny informs Doc that Jack Bennett, a deranged employee who was a former patient in the clinic, is missing along with a snowmobile. Malloy convinces Jenny to lock her room. After Doc is killed by a man wielding an axe, everyone but Malloy and Jenny think Jack is the killer. Malloy opens the safe and hands the surviving cops their sidearms. Hendricks finds a body in a frozen lake, and learns from the owner of a nearby fishing shop that the victim was a cop. Hendricks and the owner of the shop return to the clinic.
Hank, the clinic's cook Manny, and helper Gilbert, volunteer to drive through the blizzard in a pickup truck to get outside help. Malloy wants Jenny to leave as well, but she refuses. While driving away, Hank sees something in front of him and veers away from it. The truck slides off the icy road, crashing into a tree at the bottom of a ravine. Malloy and Jenny hear the crash, and Malloy hands a gun to Jenny before investigating. Malloy finds Manny murdered after he survived the crash. Malloy also finds Jack's body, the object that caused Hank to crash the truck. Malloy is startled by Gilbert approaching behind him. Gilbert, alive but scared, flees while Malloy rushes back to the clinic.
McKenzie, who is patrolling the old execution chamber, finds the machine activated. The killer electrocutes McKenzie, deactivating the building's power and heating system. Malloy forces everyone except Jenny to their cells as he realizes one of the cops is a killer impersonating a patient. Suspecting the man responsible is Mary's killer, Malloy exams Connor's body in the kitchen. Remembering the killer saying, "I see you, but you don't see me", Malloy looks inside Connor's eyelids and finds "I" on one eyelid and "CU" on the other. As Malloy and Jenny return to the cells, Hank, thinking Malloy might be the killer, knocks him out. He locks Malloy in Slater's cell and releases everyone else.
Malloy finds a vent, but as he uses a matchbook from Slater to light the cell, Malloy learns it came from a Seattle restaurant frequently visited by cops and Malloy himself, which reveals Slater as the killer as he watches policemen to learn about their habits and Malloy's. Malloy escapes the cell and finds the missing badges above Slater's room, which he collects as trophies. After establishing his innocence, Malloy has Jones and Lopez conduct patrol while Jaworski stays with Jenny in the patient room. Malloy heads into the tunnels beneath the facility.
Hank, Noah, and Slater go to the tunnels to retrieve logs for heating, with the other two unaware that Slater is the killer. Slater convinces them to split up before killing each of them. As Malloy patrols the tunnels, Slater taunts him over a CB radio and lures Malloy to Noah's hanged body where he finds the other radio. Slater is about to leave the clinic, but hears Jenny calling out Malloy's name. Malloy learns that Slater is at the tunnel's trapdoor and rushes to save Jenny.
Outside the installation, Hendricks and the fishing shop owner find Gilbert alive and bring him inside the snowcat before arriving at the rehab center. Hendricks sees Jenny's footprints and follows them. Jenny runs to a nearby shed, hiding from Slater. Malloy arrives, telling Jenny to stay inside the shed. Slater catches Hendricks before Malloy catches him from behind. Slater jumps into the shed and knocks Jenny out and wounds Hendricks. Malloy and Slater confront each other, with Malloy ultimately killing Slater.
Jenny regains consciousness and helps the wounded Hendricks walk to the clinic with Malloy, whose left arm was stabbed during the fight, following them. Malloy stops for the moment and puts the ring he was planning to propose to Mary with on a tree branch before walking away from it.