Norman Roberts, or Doc, is an Army medic assigned to an advisory team in Afghanistan’s Laghman Province in 2007, who has grown steadily disillusioned by the war. Doc is often conflicted by his non-violent humanist upbringing and a deep-seated rage that began when the North Tower fell during the Sept. 11 terror attacks, killing his father.

It doesn’t help that he’s an opium addict.

In Brandon Caro’s debut novel, “Old Silk Road,” each patrol and mission is haunted by Doc’s fear that some injury or attack — an explosion that leads to multiple casualties, or the agonizing final moments of a dying friend — might threaten his precious store of morphine, his sole escape from a reality he no longer wants any part of. Doc, his team, and the Afghan National Army soldiers they’re tasked with training, set out on a winding, deadly, and perpetually tense journey along Route 1, once called the Silk Road — the ancient thoroughfare for all of Afghanistan’s previous, and long-since dead, conquerors — in Caro’s work, published on Oct. 13.

An Afghanistan War veteran and former Navy corpsman, Caro weaves an insightful and surreal story around war, addiction, and loss of self. Through Doc’s manic inner monologue, Caro conveys what it feels like to serve in an asymmetrical war, one where the front lines and the rear are blurred to the point of nonexistence — and where your allies are as likely to kill you as the enemy you were sent to fight.

Caro captures the sense of futility that comes during those quiet moments after a bad day, in a brutal war, with no end in sight. When Doc wakes up in the back of a Humvee, strung out after shooting up, he looks around at the neat rows of vehicles — many are in varying states of disrepair — and sees the motor pool as a thinly veiled metaphor for the war effort:

It was all so structured. So squared away. … The war was often like that, it seemed. Copacetic in appearance, but in a de facto state of disorder. And though clean-shaven, trained, and even battle-tested, our ranks were staffed mostly by dropouts and fuckups — the ones who’d nearly slipped through the cracks — redeemed for our delineation of the straight path of success by our taking up the cause of war. And I was the greatest fuckup of them all.

For Doc, Afghanistan was supposed to be “the good war” in contrast to Iraq, but the more he sees, the more that ideal unravels. “Old Silk Road” is as much about a man at war as it is about a man who is unmade by war. Doc is chewed up, not by bullets or explosions, but by his own ideals and his inability to reconcile them with the brutal reality of what he sees and does.

The novel, written in the first person and following a non-linear timeline, repurposes tropes and techniques reminiscent of Joseph Conrad’s “Heart of Darkness,” and Dante’s epic poem “The Divine Comedy” to great effect. The Silk Road, for which the book is named and where much of it takes place, functions similarly to the river in Conrad’s work, with the main character moving deeper into uncertainty and addiction the more he travels on the dusty Afghan road. Doc takes on a role similar to Dante during hallucinatory encounters with Pat Tillman, who functions like Dante’s guide, Virgil. The novel takes place three years after Tillman, who turned down a professional football career to enlist in the Army, was killed by friendly fire on April 22, 2004.

Tillman goads and encourages Doc to keep moving deeper into the hellish landscape that Afghanistan becomes during the novel’s final chapters. When Doc first asks why or how Tillman is alive, the latter nonchalantly answers: “It’s complicated. … I’m mixed up in some pretty high-level shit right now. Can’t really go into detail…”

Beyond the plot twists and philosophical dilemmas that underscore this war story, the back-and-forth banter between the characters in “Old Silk Road” provides brief moments of humanity and hilarity.

While manning the Humvee turret during a convoy, Doc and his commanding officer, Captain Harold, strike up a conversation about the American dream and the unconditional love of country that is the birthright and obligation of all red-blooded American patriots.

“If ‘Murica was a woman, I’d take her out for a steak dinner on a Friday night, hold the door for her, take her coat, and pull the chair out. … Then we’d end the evening in the backseat of my Chevy Malibu, makin’ sweet love under the stars,” says Captain Harold, his rhetoric reinforcing the image of the good old Southern boy he is meant to represent.

However, like all things in this novel, the conversation is not without its pitfalls and moral quandaries delivered with just the right amount of snark.

“What if America turned out to be a dude?” is Doc’s earnest response, and one that nearly causes Captain Harold to drive off the road. “No really…what if you and America were in the backseat, about to get it on, and you reached up her skirt and came up with a handful of cock’ n’ balls? Then what?”

Intermingled with the adrenaline rush of combat and the post-high lows and shakes are those moments of banter that are simultaneously childish, vulgar, and irreverent, yet make you wonder whether you’re being let in on some essential truth, or if it really is just a dick joke.

Caro’s “Old Silk Road” is fast, hard, jarring, and leaves you longing for closure and resolution — two things that war rarely brings — until you finally get it in the novel’s last few chapters and are no longer sure that’s what you wanted.

All said, “Old Silk Road” is a compelling account of what war feels like, reading like a dying man’s last dream, with its end bringing both blissful release and genuine remorse.

Old Silk Road” (Post Hill Press, 2015) is available for purchase beginning Oct. 13.