Armstrong B. Coldmoon is a Senior Special Agent in the Federal Bureau of Investigation. He was briefly partnered with Aloysius Pendergast while working on the "Mister Brokenhearts" murders during the events of Verses for the Dead.
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.