ATLANTA

--In June 2011, this column introduced you to Sgt. Jason Cartwright and his military working dog, Isaac. Both warriors had just returned from a year of hunting for improvised explosive devices buried beneath Afghanistan's treacherous sand.

"These are real IEDs--real explosives--and everything else is out of the picture," the soldier said.

Today, Sgt. Cartwright and Isaac are once again searching for enemy bombs.

"Isaac and I left Fort Leonard Wood, Mo., on our way back to the sandbox of Afghanistan," Cartwright wrote in a September email to "The Unknown Soldiers."

The Army dog handler, who also served in Iraq, misses his wife and 4-year-old son. But Isaac, a black Labrador that saved countless American and Afghans last year, has also become family. Now, the soldier and his best friend are once again risking their lives.

"Thirteen months we were on that battlefield with all the explosions, firefights, and sights of seeing the bloody, wounded, or the open-eyed stares of the dead," Cartwright wrote. "We soon hit reality, to not only put our war faces on but also knowing our country has called on us yet again to serve."

While conventional wisdom inside the United States is that the war in Afghanistan is "winding down," the image of Cartwright and his black Lab scouring the country's unforgiving terrain for bombs that kill and maim troops and civilians, including children, challenges our perception of a conflict entering its 12th year.

"The first thing I have to do is get educated on the Taliban's tactics, as I just know they have changed," Cartwright wrote. "[I'm] hoping at the age of 5, [Isaac] will be as proficient and experienced to bring us home one more time."

While confronting a ruthless enemy, Cartwright admits to also battling the scars of his first deployment, which included finding bombs that terrorists intentionally buried near schools and hospitals.