Nancy Kress: “Probability Space” (c) 2002.

 The following lines of poetry are on the front pages of the sci fi novel “Probability Space” by Nancy Kress:

“Heaven from all creatures hides the book of fate,
All but the page prescribed, their present state.”

The lines are from the poem by Alexander Pope “An Essay on Man”, Epistle I, from stanza III (1734)

Poem source and credit: in the public domain:  The entire poem is at


Nancy Kress is an acclaimed  science fiction writer. Her fictional themes include genetic engineering (“genemod”); human-alien encounters; and states of consciousness.   Her stories are made more fascinating because they often relate to the impact of advances in science and technology on society as a whole.

Kress has won Hugo and Nebula Awards for her stories;  the John W. Campbell Memorial Award in 2009 for  “The Erdmann Nexus.
“Probability Space”  (2002) won the Theodore Sturgeon Memorial Award  for  Best Novel (2003).

“Probability Space” is the conclusion of the Probability trilogy by Nancy Kress.  The fictional world is based on Kress’s novelette, “Flowers of Aulit Prison.”

The principal events and characters in the first two novels “Probability Moon”  (2000) and “Probability Sun” (2001) , are described, to one degree or another,  in “Probability Space”.


As best as I can state it:  

The term “Probability” in physics theory applies to behavior and properties at the quantum level, of fundamental particles at the atomic and sub-atomic scale.  Kress uses string theory from physics to come up with a theory for her science fiction story: how the alien artifacts, called Protective Artifacts, may cause the destruction of the entire spacetime “fabric” of the known Universe. New fundamental particles would be formed to “repair” the fabric. And the original Universe would be reconfigured into something entirely different. A plausible science fiction theory.

The Probability trilogy is set in a time when interstellar travel and space settlements become possible after humans discover a network of Space Tunnels (star gates or wormholes) in the solar system and star systems deeper in space, built by an unknown ancient galactic alien race. The space tunnels are physical doughnut-shaped objects, made of an unknown impenetrable material, and they orbit star systems.

In Probability Space, the events are set in 2168. Mars has been well settled by now and wields more political power than Earth. The Solar system, and human settlements in various star systems are currently governed by the military, because of an ongoing war with the Fallers, an alien race in another star system. There is trouble brewing in the form of civil unrest, and a power struggle within the military.

The story is spread out over different areas:
Earth, Mars, the planet World, the Faller star system, and the Space Tunnels between the Solar System and the star systems of World and the Fallers.

There are four major characters who play a pivotal role in the final confrontation between the Fallers and the Solar System’s military :

Lyle Kaufman, now a retired military officer; earlier, he was the leader of an expedition sent to the planet World to study the  Protective Artifact found deep in the Neury Mountains. 

Marbet Grant is a Sensitive, with an extraordinary ability to sense states of mind, emotions, and thoughts and to “read” body language. When a Faller is taken captive, Marbet is given the responsibility to find a way to communicate with the alien. The information she finds from the captured Faller provides clues to the Protective Artifact.

Tom Compton, the brilliant theoretical physicist, who decodes the meaning of the prime settings on the Artifact.  The Protector Artifact is an advanced weapon, invented by the same ancient alien civilization that built the Space Tunnels. It has the same prime number settings as the tunnels. Compton’s theoretical analysis indicates that some prime number settings protect against proton-beam weapons; but there are also settings which can destroy entire star systems. If two such weapons are activated simultaneously, the result would tear apart the spacetime “fabric” of the Universe. The original Universe would be reconfigured into an unknown new Universe.

Magdalena is  a  beautiful, intelligent woman who has become the shadowy and influential power-broker in the Solar System’s politics.


As humans begin to travel beyond Earth, and its Solar System, to other star systems, they discover two existing alien races. The Fallers are spacefarers, but they are uncommunicative and warlike, and a state of war exists immediately between humans and Fallers.
The other alien race is discovered on a new planet, named “World”. The Worlders possess a unique perception of reality. All Worlders share the same reality: Conflicts, hate, disagreements cause intense physical pain. Their society and culture is therefore built on honesty, on caring and sharing. The Protective  Artifact found on their planet has affected the evolution of their brain, their consciousness of the pain and happiness of others.


Kress provides a forceful and thought-provoking ending to the story: When the Protective Artifact is used by the Solar System’s military leader to destroy the alien Fallers’ star system, the destructive waves that follow trigger the closing of the Space Tunnels. The consequences are tragic and deep. Families are cut off from each other by the closure of the tunnels. The existing space technology is not advanced enough to build star-ships to travel to other star systems, and deep space exploration is no longer possible.

Kress expresses the tragic consequences following the activation of the Artifact, through two of the major characters, Lyle Kaufman and Marbet Grant. Kaufmann looks up at the sky, at three star systems with human colonies: the constellation Draco in the Artemis star system; Han, not far from Betelgeuse in the constellation Orion; and Virgo in the Gemini system. There is now no way to travel to those colonies.

Marbet reflects on the moral responsibility that comes with the use of technology. She says that the aliens who built the Artifacts and the Space Tunnels must have thought intensely of the potential misuse of the technology. They put limits into their inventions: If the Artifact was used to destroy, the tunnels would close. The tunnels absorb the energy that would otherwise tear up the spacetime fabric of the Universe.


More from   “Probability Space”:

At the start of the story :   The political leader of the Solar System, General Stefanak now has a weapon, the Protective Artefact, to escalate the war against the Fallers. Matters become more dangerous when it is realized that the Fallers also have the same type of weapon.

The physicist Tom Capelo is kidnapped from his home in Cambridge , Mass.  His daughter, Amanda witnesses the kidnapping. Her mother Karen was killed in a Faller raid on a peaceful planet. Amanda is 14 years old. She quietly and quickly disappears from the family home, determined to find help, to find her father. Her search turns into a long, dangerous journey. and she finally makes it to Mars. Though she is naive, she is courageous, and deals with difficulties with intelligence and her father’s advice to her to stick to facts. At the end of the story, Amanda and her father are reunited.

Magdalena grew up in a poor neighborhood on Earth. She is now a shadowy and influential power-broker in the Solar System’s politics. Her son Laslo is killed when his space skimmer flies inadvertently into a restricted military zone in the far orbit regions of Mars. But Magdalena refuses to believe he is dead. She has reason to believe he is being held somewhere together with the kidnapped Tom Capelo.

As events unfold:
Kaufman, Marbet and Magdalena are on board the warship Murasaki, in orbit around the planet World.  The warship’s commander is Colonel Ethan McChesney, Intelligence Corps. Kaufman, Marbet and McChesney had worked together on the Artefact project two years ago. McChesney acknowedges that the Artifact is still on board the Murasaki. General Stefanak, the Solar System’s leader, did not want to risk having the Artifact enter the Solar System.
McChesney also reveals that the kidnapped physicist Tom Capelo is also on board the Murasaki.

By now, a coup has taken place on Mars, and Stefanak has been replaced by Admiral Pierce.  McChesney knows Pierce from way back, and he has no doubts that Pierce would use the Artifact to destroy the Fallers home star system.

Kaufman, Capelo, and Marbet are on board Magdalena’s space flyer. Magdalena flies into the Allenby and Artemis systems, towards the Space tunnel that leads into the Faller star system. Their goal is to get there before Admiral Pierce has a chance to send the Artifact into the Faller star system.

Kaufman , Marbet, Capelo suit up in environmental suits and eject from the airlock very near the space tunnel. They adjust jets on their suits to corrct direction and fly into the tunnel, towards the Fallers space.

Magdalena turns away from the space tunnel and skillfully manouvers the flyer and fires her flyer’s proton beam at the approaching Solar System warships. She watches as two warships explode. She is thinking of her son Laslo, as her flyer is hit and vaporizes.

In Faller space:
Kaufman, Capelo, and Marbet are picked up by Faller spaceships. Aboard the Faller station, Marbet uses body language, and Kaufman and Capelo make drawings to communicate to the Fallers about the imminent attack by the humans with the Artifact. Kaufman and Capelo draw various scenarios, since the Fallers have an Artifact as well. The Fallers decide to withdraw their Artifact deeper into their star system.

The Fallers allow Kaufman, Capelo, and Marbet to leave in an old Solar System military flyer. On the computer, Kaufman tracks the Faller starship as it moves towards Space tunnel 301, into Q space. Then Kaufmann sees blips enter Q space from the tunnel 218: Pierce’s warships!

The Faller Station and Pierce’s warships both explode! The Artifacts must have been activated! A destructive wave will be generated and  the surrounding spacetime fabric tears apart. It will be centuries before the wave reaches the Solar System. But the most immediate impact is on the Space Tunnels — the ones nearest to the explosion are already closing!

 Kaufman accelerates away from the explosions. They are safely out of the Tunnel and head towards the next set of tunnels. Kaufman sends alert warnings to other spaceships about the closure of the Tunnels. Any ships trying to go through will explode.

Kaufman speeds through Han’s Tunnel 117, Gemini – tunnel 64, onto Isis, Herndon, and  Solar.   And to Space Tunnel #1,  into the Solar System.

On Mars there is already a political struggle for power by different groups. General Pierce and his warships are trapped outside the solar system, on the far side of Tunnel #1. There is no returning home for them.