By Peter Watts. Tor Books, 384 pp, $32.95, hardcover.

Well, it’s about time. After four novels tracking a volatile crew trapped at the bottom of the sea, doing battle with bureaucracy and some real benthic nasties, Toronto SF author Peter Watts finally heads out into space.

And Blindsight, his first-contact psychothriller, is terrific. As in the Rifters series, his new band of misfits is cut adrift, too far out and too far gone for help. It’s 2082 and the crew of the Theseus has been launched to investigate a signal out past the Kuiper Belt, a signal that might explain why 65,536 probes had appeared one day, arrayed in an ominous surveillance-type grid, above the earth. These probes “clenched around the world like a fist, each black as the inside of an event horizon until those last bright moments when they all burned together. They screamed as they died. Every radio up to geostat groaned in unison, every infrared telescope went briefly snowblind. Ashes stained the sky for weeks.”

Blindsight is too dense with philosophy, with invention, and Watt’s shiv-sharp writing to précis. To start with, the five-person crew has been modded for optimal alien-meeting, with a multiple-personality’d linguist, a cyborg doctor, a reflex-boosted pacifist soldier, a human recording machine (our narrator, who can simulate empathy remarkably well), and—to command them—an enigmatic cloned vampire with a predator’s “omnisavantic” instincts. (Homo sapiens vampiris, Watts explains in his rigorous endnotes, “was more gracile than either Neanderthal or sapiens, although such differences were relatively minor since the lineage didn’t persist long enough for great morphological divergence”. The “Crucifix glitch” that killed them off is a conceit worth the price of the book all on its own.) Add paranoia, unchecked synesthesia, and a super-Jovian infrared emitter, and buckle up.

The novel, gripping and creepy in equal measures, builds a multivalent argument that consciousness is a looser concept than we’re accustomed to believing, opening the door to some chillingly persuasive devil’s advocacy about free will and the bounds of the individual. No one’s likable here, and certainly no one’s innocent; technology can do almost anything, and aliens are up for the rest. Yet the secrets contained in the human heart remain opaque. Is that a comfort?