The Dead Wars

Sergeant Reese Patterson, U.S. Army, is killed instantly in a mortar barrage during the second Iraq war.
Not knowing he is dead, Reese awakens thinking that he has dreamed his death. But as he watches a burial detail loading his body-bag onto a truck for shipment back to the States, he realizes the truth of his situation.
Instinctively jumping out of the path of an oncoming jeep, Reese finds himself slowly sinking into the ground. Another ghost rescues him and introduces him to a small community of the dead. They explain to him that ghosts survive on the surface the way a spider survives on water -- by maintaining a surface tension that keeps them above ground. They introduce him into the world of the dead, and also explain to him that there are two types of ghosts -- good honest folk, and the Others.
Reese learns of the doorway -- an opening into Heaven or Hell. The good ghosts, or members of the light, are trying to find a doorway into the light -- or Heaven -- and to make their way there.
Deciding that there is no reason for him to stay in the desert, he returns to the States and takes an opportunity he never had in life to visit Washington, DC.
Reese meets Corporal Stanford "Sugar Bear" Harris, a U.S. Marine killed in Vietnam. Bear educates Reese in local happenings as they walk to Arlington National Cemetery. At the Cemetery, they find Reese's grave and he discovers the mental healing power it holds for him.
Before long Reese becomes involved in an effort to save the living world from extension in a war between the ghosts.