Eric Fair’s memoir “Consequence” (Henry Holt, $26) is not just another Iraq war story about loss of innocence. Those are usually written from an infantry perspective. Mr. Fair was a civilian contractor, serving as an intelligence specialist, deeply involved in the interrogation process at Abu Ghraib, Fallujah and Baghdad in heady times, December 2003 to May 2004. He returned in May 2005 as an analyst for the NSA, serving several months. He left in need of some healing.

The story begins with his childhood in the declining steel town of Bethlehem, Pa., raised in a Presbyterian faith by schoolteacher parents. Some readers will want to race ahead to the hard stuff, but this is a spiritual autobiography, which sets up the first of many tensions. All of it counts. Mr. Fair writes of his struggles with his Christian beliefs against his actions during the war.

When Mr. Fair entered the contractor world, he had an impressive background. He enlisted in the Army in 1995 and did a five-year stint, studying Arabic in the Defense Language Institute, later being assigned to the 101st with an intelligence unit and then completing six months in Egypt. After an honorable discharge, he worked for almost a year as a police officer in his hometown. He takes the contractor position to “do his part” in the Iraq War. At Abu Ghraib, Mr. Fair enters a system that is already complicated and populated with people like a Dante circle in hell. He has to sift through what others tell him and what he sees and hears. But more so, he is not just visiting but has to participate in this charnel house without a guide.

This is when it gets fast, dense and at times, overwhelming. Mr. Fair’s writing style is workshop writing and sometimes it can get in the way of the narrative. Here though, the constant present tense, piling up of details and terse delivery help cut through the complexity of his experiences. The dark humor helps too.

Thanks to Blackwater, the military contractor business has gotten a bad name. Mr. Fair fills in some significant details. He signs on with an entity called CACI. If you haven’t heard of it, you’re not alone. (It once went by the equally nondescriptive Consolidated Analysis Center, Inc. Last month, it was awarded a $180 million contract to provide intelligence services to the U.S. Special Ops Command.)

The military base officials where he was told to report didn’t know who it was either. After no interview, no reference checks, no medical exam, no background check, he is offered, by fax, a job for $120,000 a year. There is non-stop confusion as to where he is to report, whom to report to, non-existent managers, where to stay, etc. He and his fellow contractors are not issued the promised weapons or body armor, even when going to Fallujah. They show up at designated places where no one meets them. Apparently, the military is desperate for interrogators and anyone with a security clearance will do, including a Marine helicopter mechanic. According to Mr. Fair, the whole process is disorganized and unprofessional, let alone dangerous and irresponsible.

Mr. Fair is a good interrogator, so it isn’t long until he is shown the “hard site” inside Abu Ghraib. There he sees the naked detainees; detainees dragged along the floor; the loud music cells where detainees were kept for days; the no-light cells. He hears the pleading voices.

When he does his own questioning, he has to break through the lies and non-answers and layers of Iraqi culture himself — and he realizes how some of the hard techniques get results. After his rough questioning of an Iraqi boy, the boy finally reveals a bomb shop containing large amounts of explosives, detonators and other bomb-making supplies. Again, after another interrogation using a torture chair, a detainee reveals he is guilty of facilitating the deaths of 23 Iraqi police officers.

Mr. Fair is not naïve. He knows some of these techniques are morally wrong but sometimes they produce results that save lives. He writes a chilling two-page list of all the deaths of Marines and soldiers killed by IEDs, bombs and shootings just for March 2004 alone. He doesn’t want to be part of the darker questioning, but is torn by the ambivalence that confronts him.

He takes some stands, such as turning off the loud music for a sleep-deprived detainee after another interrogator leaves for the night. Because of his ability to hear Arabic, he can cut through some of the confusion and sort out threats from people just in line looking for jobs. He assists where he can.

But, he is in bad shape and he knows it.

In a way, his acts of kindness can actually be more painful to read than the turning away from the evil acts. Against orders, he gets involved with helping two Iraqi families find out if their base-employed sons were killed in a rocket attack. His description of searching the remains is unforgettable. The wrong ID tag is with the body. When he brings in one of the fathers, they find out the remains are the other family’s son. He has to tell that family about the error. Then he has to tell the first family, who now thinks their son is alive that he too died at the hospital. When the military won’t let the ambulance take the body out to the family, he uses a CACI vehicle to do it. The grieving Iraqis’ reaction stuns him: “Walid’s father holds my hand and walks with me to the minivan. He kisses me on my cheek. … Thaer’s father does the same. He goes on his way to retrieve what’s left of his son.”

By this time, the spiritual autobiography side is getting thin. Mr. Fair comments, “This is a sin. I know it as soon as I see it. There will be no atonement for it.” By the end of his second stint, he is exhausted. The line between good and evil becomes less and less clear. Or maybe it is impossible to disentangle. He is forming an idea of what forgiveness would entail, but at the same time his new dark gnosis threatens his ability to do so. At his lowest point he says, “I am lost, and I will never get back.”

So he starts writing. He gets an op-ed piece published in The Washington Post in 2007 (and receives thousands of e-mails). He writes more. He is getting the word out. “I need to earn my way back,” he says.

A Mexican healer told author Luis Urrea, “When you write, you light a bonfire in the spirit world. It is dark there. Lost souls wander alone. Your inner flame flares up. And the lost souls gather near your light and heat … they follow the fires until they find their way home.” This is what Mr. Fair’s book can do for himself and the rest of us. No questions asked.

Hazel Solhaug, a Pittsburgh native, is a writer living in Arizona.

First Published: April 12, 2016, 4:00 a.m.