In Syria, the search is on for the remains of Americans killed by ISIS a decade ago

“It seems now that ISIS views this site as a significant burial and execution location,” said Soufan. “Maybe they chose it because of its symbolic importance, and they probably reserve it for specific or high-value or high-profile victims.”

Dabiq today is not fully secure. There are still ISIS sleeper cells in the area, according to officials from the new Syrian government that overthrew President Bashar al-Assad’s regime late last year. They are providing security for the operation, which so far has gone off without incident. The new government, which is still under U.S. sanctions, was born from an Islamic group that fought against ISIS.

This operation was only possible after Assad was overthrown. While he was in power, Dabiq was an active combat zone, making it too dangerous to carry out the slow, methodical excavation work.

Families of the hostages are aware that the operation is underway.

“This mission is really one of the most important missions anybody can do,” said Andre Khoury, a vice president with the Soufan Group and a former FBI special agent.

“We’re doing this for the families. We really want to make sure that the families have proper closure, that their loved ones lay in rest next to them. There is no better mission in the world than this mission,” he said.

“If we got lucky and we were able to do it on this trip, that would be fantastic. If not, it doesn’t mean that we are stopping. We will continue our mission. That was our pledge and our promise to the families, and we’ll continue doing that until we can bring them home,” Khoury said.