He is a graduate of Arizona State University and worked as a corporate strategic and financial planner before changing careers to become a novelist, freelance book editor, and creative writing instructor.
His novels are traditional science fiction with the common theme of the resilience of the human spirit and the ability of ordinary people, when threatened by extraordinary circumstances, to reach into themselves for the resources necessary to survive.
Forced to hunt for a solution themselves, they are woefully unprepared for the ship's malfunctions, the planet's withering heat and the mental pressures of being stranded in an alien wilderness.
He finally discovers that, due to a series of avoidable human errors, the jack-a-dandy has arrived on an unexplored planet known as Tartarus — another name for Hell.
Lost in the pitch-dark maze of the tomb, the crew is hunted by terrifying creatures — mindless, cannibalistic descendants of the original builders of the city.
The story begins when the contract courier Arlo Field is assigned to acquire and transport a mysterious alien artifact to UNSA headquarters on the planet Sierra.
An underlying positive theme of Greenleaf's novels encompasses the ability of ordinary people, when faced with adversity, to reach inside themselves for the resources necessary to overcome it.
The leader of the outlaws, Victor Troy, tries to salvage his plan by stealing a ship called the Wasp and its load of 30 interstream missiles, the deadliest weapons known to man.
High Elder Brill, the leader of Clarion's tyrannical religious cult, has been using the revelations of an alien named Lord Tem as an excuse to commit terrible atrocities.
Feeling that they have no other choice, Dorland and Paul travel to Clarion, where the only city sits on the edge of ancient ruins left by an intelligent species known as the Tal Tahir.
Joining a small band of rebels, they sneak into Elder Brill's temple and see the terrifying Lord Tem with their own eyes — and feel its mind probing theirs.
Hidden in the alien ruins, the rebels discover another member of the Tal Tahir, Elli, whose gentle nature provides a sharp contrast to Lord Tem's.
Bloodright is a departure from Greenleaf's earlier novels in that it takes place on present-day Earth, though it continues the theme that, when faced with extraordinary perils, ordinary people can reach into themselves for resources they didn’t know they possessed.
The story begins when a pair of aliens who call themselves Zeke and Simon arrive on Earth, landing their little red spaceship on a rural stretch of road in southern Arizona.
The president sends his science advisor, Kathy Stratton, and chief of staff, Ray Corbett, to Arizona to find out who the aliens are and what they want.
Making expert use of the extensive media coverage that descends on them, the "Teddies" launch an effective PR campaign that quickly brings public opinion to their side and puts pressure on the president to accept their offer.
Oscar Villalobos, a former corporate lawyer who now works as a flunkie for a local news crew, was also shocked by what he saw in the durriken's small black eyes.
While Corbett and Stratton deal with the antics of Zeke and Simon, as well as their own differences, and move closer to accepting the partnership proposal, Jamison and Villalobos slip unnoticed into the Teddies' spaceship.