What do you do when an ancient, abandoned spaceship the size of Jupiter hurtles into your galaxy from the most desolate reaches of empty space? You might do what the humans did: get there first, and then sell tickets. And you might wonder, as the millennia pass, exactly what you've got hold of.

The modern, reengineered body withstands anything and outlasts everything, so the original crew is still in charge when a queer breakthrough is made. The all-powerful Master Captain assembles her best hundred officers--including Miocene, her favorite, and Washen, the rising star--and reveals a stunning discovery. Hidden under their feet, at the vast ship's very core, lies an entire planet--a primeval world of insect-like creatures and molten iron seas. It's been given a name from ancient human biology: Marrow.

Immediately after the captains begin exploring, however, Marrow is rocked by a massive convulsion that rips their aircars from the sky, destroys every scrap of technology and--worst by far--demolishes the bridge back to the ship. When no rescue comes, they're mystified and angry; but with immortal patience they form a new plan. Marrow is expanding. In 5,000 years they'll be able to reach the ship. They have only to wait.

Regaining the ship will require industry, and industry requires hands, so the captains begin having children. But the first-born children--convinced they are the ship's builders reborn to fight their enemies, the Bleak--defect to form their own society. The captains call them Waywards.

Five thousand years later, the captains and their later progeny--though a minority on Marrow--can finally return. But the Waywards suddenly attack, using the new bridge to mount a full-scale invasion of the ship. To them, the captains and crew are Bleak--and all Bleak must die.

Across ages of humanity

Writing a novel that spans thousands of years is normally a mistake. Character development is next to impossible; even Isaac Asimov's classic Foundation reads like a patchwork. In Marrow, Reed brilliantly harvests the one true advantage of such a colossal scope, raising not one but three flourishing societies from seed to stem; yet he nullifies the usual drawback by extending the lives of his central characters through the arc of the story and beyond.

But Reed doesn't merely make his characters immortal; he mines their reengineerings and augmentations for all they're worth, adding levels of character not possible in ordinary humans. Washen's infinite forbearance allows her to settle down and wait for Marrow to expand. Her estranged friend Pamir has died horribly twice, skewing his attitude toward life. Surface-dwelling Remoras refine their cosmic-ray mutations and wear them proudly.

With all that, the key characters are still deeply human. Miocene's pride and umbrage at being marooned cracks her serenity; her own son, the visionary Wayward leader, pitilessly exploits her flaw. Washen is clear-minded and down-to-earth; she feels the sadness in how things have gone, yet she comes to see the strange, hostile planet as her home. Pamir lives with disgrace and redemption the way he has lived with death and rebirth. The most interesting character is a split personality: the seething Marrow at the heart of the huge, benign ship, its great age keeping the characters' enhanced life spans in perspective.

Marrow's narrative is clean but nuanced. The top captains, for example, address underlings in a polite yet informal manner that emphasizes both position and emotional bond. Reed can describe the magnificence of the ship and a simple clock Washen's descendents made for her with equal awe.

Marrow is one of those rare books that can take you to the end of the galaxy and back.