Night after night, U.S. patrols emerge from the sprawling Camp Victory in Baghdad to hunt for things nobody else wants to find: roadside bombs that the military calls "improvised explosive devices."
It's a costly, technology-intensive effort to counter a threat that requires relatively little investment on the part of insurgents. And even with the Americans' technological advantage, many bombs are found with nothing more sophisticated than a soldier's memory for the last location of a pile of roadside trash.
On their nighttime patrols, the U.S. Army's Ninth Engineers comb the streets trying to find and detonate roadside bombs.
"Their whole purpose is to find the IED's before they can hurt other soldiers," says First Lt. Christina Kessler, the public affairs officer for the 9th Engineers, "because they have the most survivable equipment, it's best if they're the ones that run into the IEDs."
What makes the equipment "survivable" is armor -- nearly an inch thick on all three trucks -- and a boat-like design meant to deflect an explosive blast.
On a recent night, the Dagger Ironclaw unit rumbled along a lonely road in west Baghdad -- four tall trucks, each in its own pool of bright light. Lt. David McPhail and his platoon looked for minute changes in the landscape since the last time they were here: a patch of freshly turned dirt or a cardboard box, anything that might contain a home-made bomb.
On a job known as "route clearance," Lt. McPhail's patrol includes two trucks with snouts on their front bumpers that look like huge leaf blowers. They are used to gust away debris and get a better look at potential hazards.
"So if it's an artillery shell we can see that," McPhail says, "and then you send your buffalo up there which has this big claw, and it sort of just claws at it and makes sure it is what we think it is."
The buffalo in question is the fourth vehicle in the patrol, towering over the armored trucks. Rather than an animal, it looks more like a medieval siege engine, with its row of small, thick-lensed windows and an iron-clawed arm folded on its roof.
"We call that the 'spork,' kind of like the little lunch fork or spoon," McPhail says. "It's got the spike on one end and the scoop. I guess the best way to look for an IED is, if you think it's buried, is to dig it and plop. And if it blows up it's better than having it blow up on a vehicle."
In official military jargon, that process is called "interrogating" the target.
When it's patrolling on the dark road, the buffalo's spotlights cast a wide skirt of light behind its smaller escorts, throwing long shadows back among the heaps of garbage and debris in vacant lots and dimly lighted buildings.
It's hard to imagine how anyone could tell if something in this landscape has changed.
"You'll see it. It'll be out of place," McPhail says. "Like, the garbage is garbage, but then you see something that just doesn't look right. These guys know it all. They've got junk memorized. I have dreams at night of garbage."
Among the things Dagger Ironclaw finds most often are the victims of sectarian violence in this border area between the Shiite neighborhood called Shula and the Sunni neighborhood of Ghazaliyah.
Major David Ray says it takes an unusual combination of qualities to keep at this mission, night after night.
"I think most important is soldiers have to be well-trained and have confidence in their equipment," Ray says. "And then, I don't want to say a little bit crazy, but that's how they're looked at by all the other members of the combat brigade team."
As Capt. Tim Russell, the unit's route planning officer, says, "These guys are special because their whole job is to go out there to find something that could potentially blow them up."
On patrol, it is disorienting to watch the long shadows flicker past, hour after hour.
Burnt-out hulks of automobiles start to look like the skulls of prehistoric fish.
The only live things out here are the packs of wild dogs that look up from whatever they're feeding on, startled by the light.
The only things out tonight are the dogs, Dagger Ironclaw, and the bombs.
It'll be another hour before the patrol goes home.