Once upon a time, science fiction experienced a period of volatile experimentation in form, content and approach called the New Wave.

From 1964 through the early '70s, a group of writers challenged the established, rather pulpish traditions of science fiction and attempted to transform it into a form equal to the best literature. Like so much of that era, it was marked by excess, though it did succeed in elevating the general quality of writing in the genre.

Among the most problematic artists of the period was Robert Silverberg. Not a new writer — his first novel was published in 1955 — he proved to be one of the greatest beneficiaries of the New Wave. Several of his novels of the period are prime examples of the possibilities of written science fiction, and PYR has reissued one of them.

"Son of Man," originally published in 1971, is more parable than novel. Clay awakes in the far, far future to find an Earth whereon evolution has split humanity into several distinct subspecies. He is taken in tow by a group of Skimmers, who most closely resemble what he thinks of as human and yet are far more mutable than anything in Clay's experience. They can travel through space at will, switch gender, and even "die" and then return to talk about it.

The Earth is subdivided into regions that seem to possess conscious qualities and unique personalities.

Clay goes on a long odyssey of discovery across this profoundly altered landscape, undergoing his own transformations with each new form of humanity encountered, until he reaches the point of spiritual synergy and subsumes the essence of all into himself, becoming a diminutive Christ figure.

As an example of New Wave writing, "Son of Man" is as good an example as can be found, displaying clarity as well as breadth. Yet its sensibilities seem inseparable with the era in which it was written. A fascinating experiment, historically relevant in the history of the genre.

The world in Daryl Gregory's first novel, "Pandemonium," is much like ours, with one major difference: Demonic possession is an established fact, its present-day manifestations having begun sometime just after World War II.

Del Pierce is a young man who is a survivor of such possession. At age 5, he fell victim to a demon called the Hellion, a creature that chose pre-adolescents, who could turn a child into a terror. Del, with the aid of a loving family, managed to survive.

But now, in his 20s, in the wake of a car accident, he is re-experiencing some of the traumas of those days of possession. After losing his job, he returns home to Chicago, in search of a doctor who might have the answer to what happened to him and what may be happening again.

But the doctor is murdered and Del — or the demon he grows convinced has become trapped inside him — may be responsible. With his older brother, he tracks down a priestess who has had success with exorcism. She decides to help him find out whether he is under assault again or has, in fact, locked the Hellion inside.

Gregory's first-person narrative flows smoothly, not once falling to the easy symbology of religious arcana or trite horror story explanations.

The answers, when they come, are surprising and unsentimentally satisfying. A very worthy effort for a practiced hand, but especially fine for a first novelist.

"Agent to the Stars" is a first-contact novel. But as in other John Scalzi novels, nothing is as straightforward as it might be. Or, rather, it is straightforward in the most unexpected ways. Instead of contacting a government or a religious leader or even some isolated people in a rural community, the aliens in this novel purposefully choose to contact a Hollywood agent.

The Yherajk have been watching our movies and television shows, as well as listening to our radio broadcasts, for decades. They have taken in our world so well that they understand how much of it works socially.

They also realize that they have a profound problem when it comes to introducing themselves to humanity: image. The Yherajk are colony creatures that resemble the Blob. Plus they communicate primarily by smell, most of their vocabulary being rather noxious to humans.

They pick Carl Lupo, head of one of the best agencies in Los Angeles. Carl in turn hands the problem over to one of his newer agents, Tom Stein, who gamely tries to come up with a strategy for turning what could be a diplomatic disaster into a world-class event.

Scalzi plays it straight, which makes the humor richer — all the more so because the events that transpire, given the premise, are so thoroughly plausible. Between the comic moments, there is a well-conceived, first-rate novel about expectations and the power of perception.

Mark W. Tiedemann is the author of "The Secantis Sequence" and "Remains." He is president of the Missouri Center for the Book and lives in St. Louis.