Armstrong B. Coldmoon is a Senior Special Agent in the Federal Bureau of Investigation. He is on occasion partnered with Aloysius Pendergast at the request of Assistant Director in Charge Walter Pickett.
Coldmoon is an Oglala Lakota who grew up in Porcupine, South Dakota, on the Pine Ridge Reservation, the son of a Lakota father and Italian mother. Tall, trim, and fine-featured with a swimmer's build, he has long jet black hair, pale green eyes, and olive skin.
When he was eleven years old, Coldmoon's father was murdered in a bar fight. The killer's close relationship with the tribal police paid off: there was no investigation, and because it occurred on the reservation, local and state police had no jurisdiction, while the federal authorities simply wrote it off. The ordeal ultimately inspired Coldmoon to pursue a career with the FBI, where he successfully closed the case.
Coldmoon joined the FBI after finishing college at the top of his class. When he graduated from the Academy, he secured a rotation to the South Dakota resident agency in Aberdeen, where his first case was to bring his father's killer to justice.
He spent the next eight years in distinguished service in the Cyber Division and Criminal Investigative Division, earning the FBI Shield of Bravery for meritorious service for an undercover operation in Philadelphia. He was eventually assigned by New York Assistant Director in Charge Walter Pickett as a partner to notorious lone wolf Special Agent Aloysius Pendergast.
Coldmoon's service weapon is a 9mm Browning Hi-Power that his great-uncle had carried during World War II.
The Brokenhearts Murders
Coldmoon's first case with Pendergast took them to Miami, Florida, to investigate the murder of Felice Montera. In addition to having her throat slit, Montera's heart had been cut out and placed on the grave of Elise Baxter, a decade-old suicide, along with a note from the killer, signed "Mister Brokenhearts." Coldmoon, who had secretly been tasked by Pickett with monitoring Pendergast's unorthodox investigative methods, had some initial difficulty getting on the same page with his new senior partner—including literally being left behind when Pendergast traveled to Miami a day before their scheduled flight. However, to Pickett's surprise, Coldmoon supported Pendergast's insistence that they investigate Katahdin, Maine, where Baxter had died, offering only a short "I go with my partner" as explanation to a curious Pendergast. Ultimately, the trip to Maine yielded little from an investigative standpoint, and to make matters worse, Mister Brokenhearts claimed a second victim, Jennifer Rosen, while they were away.
They returned to Miami just in time for the discovery of Rosen's heart, which had been removed in an identical manner to Montera's. A caretaker had discovered it in the mausoleum vault of Agatha Flayley, another old suicide that had occurred just four months after Elise Baxter. Though their shared competence had begun to build a mutual respect between the two agents, Coldmoon—still smarting from the fruitless excursion to Katahdin—chose not to speak up when Pendergast again requested that they look into the suicide victim, who had been found in Ithaca in upstate New York. Nevertheless, Pickett warily approved the trip, with the provision they return the same day, and Coldmoon found himself flying into Syracuse the following morning. They learned little more in Ithaca than they did in Maine, though Coldmoon did manage to take a detour to the federal penitentiary in Jamesville to visit his father's killer before heading back to Florida.
In the midst of Mister Brokenhearts's third murder, whose heart was left inside a jar of ashes of yet another suicide victim from several years before, Coldmoon's resolve in his secondary assignment from Pickett soon began to clash with his instinctive loyalty to his partner. When Pendergast's exhumation of Elise Baxter—despite the disapproval of both Pickett and Baxter's parents—gave Pickett the opening he needed to take Pendergast off the case and transfer him out of the New York office, Coldmoon ultimately backed Pendergast, leaving Pickett no choice but to draft transfer orders for both agents. Before the orders became official, however, assistant medical examiner Dr. Charlotte Fauchet discovered that all three suicides had, in fact, been homicide victims, killed in the same manner and staged to look like self-inflicted hangings. Pickett quickly rescinded the orders, instead leaving Coldmoon and Pendergast free to work without interference.
Working with Dr. Fauchet and Gordon Grove, a commander in the Miami Police Department and liaison for external affairs, their investigation eventually led them to former marine John Vance, who had returned twelve years earlier from two tours in Iraq and Okinawa to find his wife Lydia dead of an apparent suicide. Vance insisted that his wife had been murdered. Coldmoon and Pendergast ventured out to meet with Vance at an old hunting camp owned by the Vance family for decades. As they reached the camp's main building, they plunged into a sinkhole, and as they struggled to climb out, Coldmoon was shot in the back by a hunting rifle. He clung to consciousness at the bottom of the sinkhole for several agonizing minutes before Pendergast returned for him along with another younger man, a stranger.
Coldmoon awoke in the University of Miami hospital after extensive surgery. Walter Pickett arrived with Dr. Fauchet and Agent Pendergast to let him know that the case was closed, with Mister Brokenhearts in custody. Pickett informed him that he was being promoted to Senior Special Agent and had been awarded the FBI Star for his role in the investigation; Pickett himself had been offered a position in Washington and was leaving New York and the Criminal, Cyber, Response and Services Branch for the National Security Branch. Coldmoon's only condition of acceptance of his promotion was that he be reassigned to a different partner, knowing that Pendergast—though the senior agent had grown to respect him and accept their partnership—would still rather work alone.
Post-Brokenhearts and Pendergast Reunion
After being released from the hospital, Coldmoon boarded a southbound bus from Miami and impulsively disembarked in Islamorada in the Keys. He took up residence in a small tiki hut community, spending his days drinking beer and his notorious coffee in the sun, where Pendergast found him—unshaven, unkempt, and uninterested—to recruit him for the events of Crooked River. After Pendergast brought him to Sanibel and got him up to speed on the case, Coldmoon suddenly found himself bound for Guatemala, looking for the family of one of the victims. The search turned up a coyote operation that had accepted a bribe to turn over a large number of emigrants to what they thought was an ICE bust.
Coldmoon's return to Florida was diverted from Fort Myers to Tallahassee due to thunderstorms. He finally touched down to a ringing phone: Constance Greene, with news that Pendergast had been ambushed and abducted. Following a clue left behind by Pendergast, Coldmoon and Constance—with the help of Google Maps—pinpointed the location where Pendergast had been taken: an old sugarcane processing plant on Crooked River, serendipitously just a ninety minute drive from Tallahassee, as opposed to almost seven hours from Fort Myers. After explaining to Constance the impracticality of waiting for her, Coldmoon set out on a solo rescue operation; Constance Greene, meanwhile, launched her own attempt by first enlisting Sanibel Police Chief P. B. Perelman's boat (and eventually, Perelman himself) to take her directly to Crooked River via the Gulf of Mexico.
Under cover of the arriving thunderstorm, Coldmoon was able to infiltrate the plant, which had been converted to a military-style installation housing a laboratory complex. He located Pendergast just as the senior agent was about to be subjected to the fruits of the lab's research: a serum that triggers acute Body Integrity Identity Disorder. The agents very nearly successfully fought their way out of the complex before running out of ammunition, but were saved by the timely arrival of Constance Greene.
Coldmoon spent the following week vacationing on a private island with Pendergast and his ward. Their official reports were careful to leave out any of Constance's involvement. As their vacation ended, Walter Pickett arrived, confirming that Coldmoon was headed for his new post in the Colorado field office and that Pendergast was returning to New York. The Assistant Director in Charge hinted at a new assignment in Savannah, Georgia, that he would have liked to partners to unofficially look into.