1st Lt. Nelson DeMille celebrates Christmas 1967 on the white sands of Bong Son, Vietnam.

The future author takes a break outside a cottage in Bong Son.

The Bong Son Valley was a free-fire zone at the time DeMille served there.

Inside a headquarters tent at LZ Sharon in Quang Tri province in August 1968, DeMille serves as company executive officer.

A 1997 return visit to Vietnam revealed that much of the war damage, such as this school in Quang Tri, was never repaired.

Like many U.S. military vehicles, planes and equipment, a B-52 bomber remained where it went down at this lake in Hanoi in 1997.

Nelson DeMille’s combat helmet is displayed proudly in his office.

The author’s walls are covered with certificates, citations and photos not from his literary career, but from his time in the Army.

In 2010, DeMille was surprised when a group of veterans with whom he had served in Vietnam met him at a book-signing event in Florida and presented him this ceremonial sword.

At his home on Long Island.

The author who writes all of his books with pencil on yellow pads works at his office.