Bestselling author L. E. Modesitt, Jr. begins his Ghost Books series with Of Tangible Ghosts in a strange alternate reality where ghosts are no longer mere superstition, but physical realities.

When two real ghosts and the records of a murdered researcher enter the life of Johan Eschbach, the former spy and present professor finds himself caught with the secret of high-technology de-ghosting, and the whole world, including his former spymasters, try to turn Johan himself into another ghost.

The Ghost Books
#1 Of Tangible Ghosts
#2 The Ghost of the Revelator
#3 Ghost of the White Nights
#1-2 Ghosts of Columbia

Other Series by L.E. Modesitt, Jr.
The Saga of Recluce
The Imager Portfolio
The Corean Chronicles
The Spellsong Cycle
The Ghost Books
The Ecolitan Matter
The Forever Hero
Timegod's World

Other Books
The Green Progression
Hammer of Darkness
The Parafaith War
Adiamante
Gravity Dreams
The Octagonal Raven
Archform: Beauty
The Ethos Effect
Flash
The Eternity Artifact
The Elysium Commission
Viewpoints Critical
Haze
Empress of Eternity
The One-Eyed Man
Solar Express