Ellen Starke is regrowing her body, but there's something not right in her head. Given how little of it was rescued from the star-yacht crash that supposedly killed her mother, Eleanor, it's a wonder she's alive at all . . . and getting her head back into the hands of the family business was an adventure in itself. Fred could tell you the whole story . . . but he probably wouldn't want to. He's a russ, you see, and russes are like that—loyal, tight-lipped, ever mindful of their duty to their employer. Even when it's not clear exactly who their employer is, and even after that loyalty has landed them in prison on charges of murder, not to mention causing a planet-wide panic over the possibility of clone fatigue in the process. Fred's court case is nearly over, and the result will change his life—and the life of all other clones—whichever way it goes.

Meanwhile, Bishop Merrill Meewee has problems of his own. The Garden Earth Project corporation is being derailed by boardroom shenanigans in the absence of the Starkes, and Meewee's dream of sending out ark ships to terraform and colonise new planets threatens to fragment into exactly the sort of corporate grasping that it was meant to make amends for. The Earth is crowded and broken, and the only way to fix it is to decant its massive population and allow it a chance to recuperate. But Meewee's fellow directors think that the same end can be accomplished by using the ships as in-system habitats, leaving behind them a clear Earth . . . and a clearer route to their own profit and power. But even Meewee and the directors don't know the whole plan, or suspect who is masterminding it all.

David Marusek's second published novel, Mind Over Ship, follows on from the events of Counting Heads (2005). I could easily expend twice my wordcount trying to summarise the latter, and the same amount again trying to sketch out the bulk of the plot in Mind Over Ship. To say that Marusek's work is dense is like saying that uranium is a bit heavy; this book contains enough science fictional Big Ideas to fuel half a dozen novels, and probably their sequels as well: colonisation ships; the Crowded Earth; clones; partial post-scarcity class war and economics; the technological singularity; posthumanism; near-sentient artificial intelligences and near-perfect simulations of real people; multiple intersecting layers of simulated reality and virtual personality; nano- and biotech, wide-scale genetic modification and rejuvenation technology. I didn't notice a kitchen sink, but I'd not be surprised to find I had nearly stubbed my toe on it while busily gawking at something else.

Most amazing of all—and most challenging, even to a practised reader of idea-heavy science fiction in the modern mode—is the almost total lack of infodump. Amazing, because Marusek's invented world works perfectly, like some insanely complex orrery of ideas interlocking and turning in synchronisation, nothing unnecessary included. Challenging, because the reader is thrown into the deep end without a float to cling to. You don't inhabit the world of Mind Over Ship. You learn to breathe it, or you drown.

Perhaps "difficult" would be an even more appropriate term, provided I make it abundantly clear that I intend it as a compliment. Even having read Counting Heads, my brain was working overtime just a few pages into Mind Over Ship; the dizzying array of characters, plots, tropes, and neologisms demands total attention from the get-go. Watch how Marusek crams in the detail of an urban scene as Fred goes out for a constitutional, dropping classic megalopolis tropes and compressed nouns almost in passing:

A few floors down, Fred paused at the pedway merging ramp to shape his floppy hat into a cycling helmet. [ . . . ]

Fred sprinted onto the pedway and entered a jogging lane. After building up a little speed, he began a skating stride, pushing his cross-trainers sideways with each step, and the pedway plates beneath his feet slipped into skate mode. When he was skating fast enough, he merged with the velolane. Just then, the pedway emerged from the interior of the gigatower, and he was suspended two hundred munilevels over a traffic well. (pp. 119-20)

Beneath the imaginatory detail and filigree, however, is a well of compassion for the human condition, balanced by a wry (and occasionally very dark) humour. Mind Over Ship is science fiction at its most fearsome and sharp, but at its core are stories about people. This will come as no surprise to those who've read some of Marusek's short fiction. "The Wedding Album" (1999), one of the stories that solidified his reputation as a writer to watch, is a head-twisting tale about virtual realities and bandwidth scarcity, but the reason the story has legs lies in the couple at the centre of the narrative: a virtual simulation of a pair of newlyweds trapped in a small slice of time and memory like human flies in digital amber. Marusek knows human drama, and writes it so subtly you hardly notice that it's actually centre stage the whole time, right up until he plucks your heart out.

Mind Over Ship, then, has two core stories. The first is much like that of "The Wedding Album," in that it's the story of a couple struggling to keep themselves and their relationship together in the face of outside pressures. I mentioned Fred in my introduction; he's married to Mary, who is also a clone (or "iterant," as polite society likes to call them) of the evangeline line, whose progenitor was selected for her innate empathy. While Fred's been stewing in the prison system (awaiting the verdict on the part he played in rescuing Ellen Starke's head in the preceding novel), Mary has risen to a level of fame practically unheard of for an iterant, bringing her almost in line with the lower levels of the "affs"—the affluent and the non-cloned. As such, she has a character based on her which appears in virtual telenovelas and brings in a good income alongside her job in Ellen Starke's household, and in Fred she has the ideal husband—evangelines almost always settle down with the stolid and practical russes, you see.

But Fred's russ nature is no benefit in his current position; indeed, it's a hindrance. He resents having been bamboozled by the Starke household (by manipulation of the devotion to duty that marks his line) into the culminating moments of the mission to rescue Ellen's head, during which he killed a brother clone. As such, he's not particularly pleased with Mary's closeness to Ellen. Nor with his position at the centre of a debate about whether clones could act "out of character" when they're getting old, the shadow of which has turned the rest of the russ fraternity against him and rendered him not just persona non grata but utterly unemployable in jobs commensurate with the russ skill set. Nor is he pleased with the constant media attention all this brings with it; russes just want to get on with their lives. Poor Fred can hardly find his life for looking.

It's Fred and Mary's story that ties the whole book together, but it takes a while to realise that. So many of their problems are external that they could seem like stool-pigeons for Marusek's world-building, if not for the fact that the natural friction and inevitable love between them—and all the drama and compromise that come with it—has you emotionally invested in their story very quickly. At this level, Mind Over Ship is a love story of the old-fashioned kind.

The second major thread is that of Merrill Meewee, a man whose dreams of re-enfranchising the teeming masses of the third world by giving them new planets to live on has grown into the Garden Earth Project. The ships of the title—vast O-rings designed to be propelled away from Earth by energy beams and carrying hundreds of thousands of would-be colonists—are his grail, and he has already made a number of concessions to keep the great plan together. Meewee comes across as a kind of pragmatic idealist—he knows what he wants to achieve, but has been forced by circumstance to accept that the ends must justify the means in bringing his vision to fruition. As the plot progresses (and the hyenas circle closer), Meewee must make an unwitting Faustian bargain to snatch the GEP back from the hands of the plutocrats, but that choice may well spell a different kind of doom for humanity . . . at least, for humanity as Meewee defines the term. His story is that of a person struggling against the odds to achieve his goal without compromising his own sense of ethics; he doesn't get an easy ride, to say the least.

These core threads are bolstered with a skein of subplots and minor characters; there is no shortage of story, though Marusek's short fragmentary scenes and web-culture jump-cuts are tough work, and the sheer volume of material (not to mention bizarrely named characters) makes it easy to get lost in the scenery while the tour-guide is showing you something that will become important further on.

Or perhaps my mind-set makes it easy to forgive what others have perceived as Marusek's principal flaw—namely that the story suffers under a surplus of stuff. I'm a sucker for stuff, though; that's why I got into science fiction in the first place. It has been said that science fiction is set in the future while actually being about the time in which it is written; if you concede that point, Mind Over Ship is a textbook example of our current political and philosophical concerns made manifest in a fictional future.

For example, are we more than our genetics? Fred's existential angst makes the question personal, but the clone fatigue scare highlights a world where the thought of deviation from predetermined behaviour (at least on the part of iterants) is horrifying, both morally and economically. Parallels with the current global obsession with immigration are clear to see; the clones have their own scale of social status, but they are condemned to be un-people, forever of lower status than the affs—they were designed as servants, and as servants they must stay. Cloning is not a new theme to SF by any means, but Marusek's humanisation of the iterant characters forces us to examine the institutionalised fear of the other as being as much a function of socioeconomics as genetics, and Fred's struggle to transcend his predetermined role while staying true to his own sense of selfhood will resonate with anyone who has ever felt they weren't sure who they were really meant to be.

Or how about complete media saturation? In a similar manner to Ian McDonald, Marusek sees the fictional and factual media spheres merging—not just into one another, but into reality as well. Software actors based loosely on real celebrities act out soap operas in the homes and offices of their viewers; virtual proxies of the powerful can be despatched to conduct important business deals while the "original" lounges in bed; and for Fred to escape media attention as he so dearly desires (or for anyone at all to reach anything even approaching true privacy and secrecy) means purging his entire body of the nanoscale nits that spy, track, observe, and record. It's a saturated postmodernism, a culture that can't tear its narcissistic gaze away from its own reflection, telescoping away ad infinitum as if in a cube of mirrors . . . a future that may be technologically inconceivable (though only just), but which seems culturally inevitable.

I could go on—hell, I'd love to go on—but I mustn't. So let's put it this way: would I recommend Mind Over Ship? Yes, and vigorously, but not without reservation—it is a book that demands a mastery of the full established suite of SF reading tools.

Can Mind Over Ship be read without having read Counting Heads? Again, yes, but I'd still recommend reading Counting Heads first, if only because you'll get into Mind Over Ship faster as a result—but also because, if we want to support writers who are pushing the boundaries of the genre, we need to buy as many of their books as we can so that someone keeps publishing them. Change happens at the edge of things, not the centre . . . and Marusek is a long way out from the habitable zones near the sun.

Paul Graham Raven is a freelance writer, editor, publicist and web-presence manager to busy independent creatives, and PR guy for PS Publishing, the UK's foremost boutique genre press. He's also ed-in-chief of near-future SF webzine Futurismic, a learning fictioneer and poet, a reviewer of books, music and concerts, a cack-handed third guitarist for a fuzz-rock band, and in need of a proper haircut.