In Hollywood terms, it's high concept: in a world where religion is banned, what happens when robots find God?

This is an exaggeration: religion is affected in only some parts of the near-future world of Ken MacLeod's latest novel, where it has been not so much "banned" as forced out of public life. Battle-weary from years of fighting radical Islamism, and seeking someone to blame for the ruinous consequences, public opinion in the US and the UK has turned a royally pissed off gaze upon the belligerent faithful within. Religious extremism has been cast out—and, Richard Dawkins-style, all its mild cousins along with it. In the process, the US was plunged into another Civil War and the UK split into its constituent parts, but at length the militants of all stripes were expelled. By 2037, when The Night Sessions is set, the scapegoats have been banished from view for some time: out of sight and, for most people, out of mind. (Perhaps too soon out of mind; there are several occasions during the book when characters' lack of even basic knowledge about, say, the hierarchy of Church authority smacks not of years elapsed but of generations.) Religious observance continues, but it is a private matter now, a slightly embarrassing habit to which the police turn a blind eye unless it is actively causing trouble.

Then the body of a clandestine Catholic priest turns up in Edinburgh, with what appear to be the ingredients for a bomb in his flat. DI Adam Ferguson, a veteran of the "God squads"—police task forces that were assigned to monitor (and harass) religious institutions, back before what is variously termed the Second Enlightenment (by the secular) or the Great Rejection (by the religious)—gets that sinking feeling:

It had been straightforward back in the old days, when the God squads had their boots on the floor of every church, chapel, synagogue and mosque in the land. Ferguson found himself blushing at the recollection of some of the things he'd done then. Non-cognisance was now the modus vivendi. (p. 42)

"Blushing" would be a rather incongruous term to use of a hardened copper. But Ferguson is not, in fact, full of world-weary belligerence. During a discussion at this year's Edinburgh International Books Festival, MacLeod talked up the idea of Ferguson as the "anti-Rebus," and his protagonist is a surprisingly earnest, by-the-book type, happily married and at best a moderate drinker. All this often makes for a wryer, lighter tone than might be expected from what is otherwise rather grim subject matter:

Later that evening he surprised Isla [his wife] by telling her that he had an early start on the Sunday morning, because he was going to church.

"Try not to attack anyone," she said. (p. 187)

It is an interesting choice, but one that teeters on the dissatisfying; Ferguson's characterisation humanises the novel, but never really energises it. The first of these consequences is unusual, and welcome, for a hero in this type of story, but the latter means that he, and we, are left waiting too long for the race-against-time aspect of the plot to kick in, and start driving things forward. Ferguson is, at heart, a nice, stolid, well-meaning sort of bloke. But is a blush really all he can muster at the recollection of police brutality? Later we are told that "He never remembered it without shame" (p. 81). Later still, we get his unsettling recollection of the first time he used violence against a suspect ("as he looked in shocked disbelief at the blood on the metal and the welt on the cheek, he'd realised something [...] You don't feel other people's pain" (p. 264)). But by then the pipe and slippers image has already set in.

Still odder is Ferguson's confusion at the fact that pushing religious belief underground might have only made it more fanatical:

"It's not like the bad times, yet," he said to Isla. "I don't think it'll come to that. What gives me the creeps is the thought that something like this can still happen, after... all we did back then." (p. 81)

The notion it would not create problems to give fundamentalist believers—people with a ready-made assumption that this world is but a pale, doomed reflection of the much better one in which they are going to live forever—more to kick against, and less to lose, is redolent of the inability of certain mindsets to understand the strength of both religion and desperation. But for someone like Ferguson, who has lived through many long years of violence in the name of religion and observed the process first-hand in the past, it reads like selective character stupidity—or a deep sense of denial born of guilt that simply is not supported elsewhere in the text.

Not all the characters are so sedate, although none of them get as much point-of-view time with the reader—and, as is often the case in MacLeod's novels, such three-dimensionality as they have arises as much from what we can infer, knowing the type, as from what is actually said through their (largely plot-servicing) words and deeds. Most of the characters are background plot devices at best; they do not really come alive, or illuminate for us what it is like to live in this world. A few do stand out, however. Fellow copper Mikhail Aliyev, for example, is nicknamed "the kinky Kazakh" for his evenings-and-weekends transvestism, and spends much of the book having threesomes with a "silent scene" DJ (in the clubs of future, you only have to hear the music if you tune into it) and his forthright graduate student girlfriend—all in the name of investigation, you understand.

At the other end of the spectrum—or so he keeps telling himself—is John Richard Campbell, a young engineer, and true believer, from New Zealand. New Zealand has not implemented any ban on public religious institutions, and as such has become a haven for American Evangelical exiles. There are fascinating glimpses of the impact the refugees have had on Kiwi religious expression; they have narrowed the definition of acceptable Christianity by, for example, closing down the space in which syncretistic churches, drawing on both Maori and Christian traditions, operate. (Alas, these are only glimpses; much like in his approach to his characters' inner lives, MacLeod seems largely uninterested in exploring either of his settings beyond what is essential to the main story.) Campbell works in a national park that is funded by the exiles as an open-air creationist museum. Believing that robots might have souls, he preaches the Gospel to the park's robots—employed as 'living' natural history exhibits—in his spare time.

There is something slightly mechanical about Campbell—ironic, given his customary audience. He's naïve and earnest, but not without an aggressive spirit when he feels himself provoked:

"It's the fucking Christians."

"I'm a fu—a fundamentalist Christian myself," said Campbell, stung into remonstrance.

"The more fool you, young man." (p. 6)

Much of the time, though, he has the serene self-control and the pre-rehearsed speech of one who lives by applying a series of maxims to every situation, rather than responding from experience or empathy. There are signs, early on, that Campbell has considerable intelligence and sensitivity, and it is an open question whether making him almost robotic in his intolerant irrationality is a useful comment on the effects of fundamentalism, a needless weighting of the dice towards the secular in the book's consideration of religion, or both; certainly, it is less nuanced than it might be.

Although she is a much more minor player in the proceedings, academic Grace Mazvabo provides a more interesting portrait of an intelligent person of faith—insightful and wrongheaded by turns, and much more human—as well as some much-needed perspective on how religion has shaped Scotland's history. She sees it as "a tradition entwined inextricably with the nation's past all the way back to Columba's coracle precariously ferrying the faith across the Irish Sea," a "voice" whose utter rejection harms the country, costing it "a way of making sense of itself" (pp. 197-8). (There's also something peculiarly, splendidly Scottish about her rueful image of the Church as "a perpetual grey cloud drizzling on the nation's spirit.") She does not say—she does not need to—that it is arguably this very rejection, this willed ignorance of the lessons of the past, that contributes to the escalation of events Ferguson and his team are attempting to stop. It is not simply that outlawing public religion has made some of its adherents crazier. Lacking the frame of reference of past religious conflicts on their own soil—stark in the history books, and in the tracts produced by the latest fanatics, but no longer taught in the schools of 2037—neither Ferguson's team nor his superiors give proper credence to what belief (and the orders of its earthly mediators) might inspire, and what battles are still being fought, until it is too late.

Unbeknownst to Campbell, some of "his" robots have been broadcasting his message to brethren on the other side of the world, and his sermons—nicknamed the "Night Sessions," due to the time difference—have come to the attention of a rather exclusive little sect in Scotland. As Christian churches, particularly Protestant ones, seem so endlessly wont to do—something that is underlined for us by the snippets of Scotland's turbulent religious history that come up during the detectives' investigations—the sect considers itself in schism, separate from all other (defective) believers:

"The Churches here have all compromised! [...] There is only one congregation left of the one true covenanted reformed Church of Scotland, and that is us. We have no ordained minister, no student for the ministry, no synod or assembly. We have only our members, our adherents, and this Kirk Session. We are the remnant." (p. 20)

More significantly, Campbell's message has resonated with certain robots. At first, it is easy to overlook the robots as SFnal window-dressing, despite the flippant, appealingly cheeky opening of the novel ("'Science fiction,' said the robot, 'has become science fact!'" (p. 3); Campbell, observing, immediately and obligingly groans, presumably on behalf of those readers who find cheeky less appealing). Their ubiquity in this world—as security guards, as museum exhibits, as tech support—makes them invisible, which is of course something the plot turns upon. But it is in robots that the book's most interesting treatment of its themes lies: robots as underclass, robots as returned soldiers unwanted by society, robots as the desperate overlooked searching for some other purpose in life.

Ferguson's partner is a robot. Skulk, short for Skullcrusher, is a "leki"—a small Tripod-esque robot adapted for crime scene investigation and sniffing out lies during interrogations. The buddy-cop dynamic that would be usual in these situations is, by necessity, limited; Ferguson and Skulk have a working relationship that is evidently built on long, close association, and they share some banter, but they can hardly have a pint together after hours. Indeed, Ferguson's empathy towards the robot—specifically, towards the fact that it has failed to "get over" the "traumatic experience" of being switched from the body of a combat-mech to its present "degraded" mini-tripod form—is stunted at best ("Tough shit" (p. 110), in fact, reflecting that a robot could not be trusted in control of such weaponry). It is through Skulk that MacLeod explores the mindset of robotic suicide bombers: unshakable in following commands, inexorable once a decision is made, and secure in the knowledge that death is not the end (if not heaven, there is definitely a back-up). This is implicit in the actions of the villain of the piece, but made explicit in a Skulk point-of-view commentary. Here is an off-shoot Skulk sent on a suicidal mission to stop another robot bent on the same course, to different ends:

Skulk2 toggled, then, to self-sacrifice mode. No longer was Skulk2 troubled by its ultimate, and doubtless not distant, fate. Its motives were now subsumed in the completion of its mission, its empathies now mobilised on the side of Hardcastle's past and possible future victims, and its self-interest concentrated on burning out the shame of its own part in the shame of the team's failure to prevent that renegade robot's crimes. (p. 275)

The Night Sessions is a fast, entertaining read with some challenging ideas behind it. The problem—as with MacLeod's Learning the World (2005)—is that it all feels just a little too thin to properly service the ideas and the environment they have created. It is a short book, written in what is by now MacLeod's trademark sparse prose. Neither of these things are an automatic disadvantage in themselves, as the brilliant The Execution Channel proved last year. But that had a strong, pacy central thematic thread that could ride out some of the gaps in the characterisation. Furthermore, The Execution Channel really was a five minutes into the future—or five minutes into an alternative timeline, as it happened—scenario, an instantly recognisable extrapolation of our own time. The break that The Night Sessions presents is much more fundamental, and the fact that so many of the characters are so flat and plot-functional helps not at all to sketch in the details of what it feels like to live in this future. Still, if The Night Sessions' conclusion is not quite as audacious as that of the previous novel, it is nevertheless strikingly brutal and brave, a welcome sign of a novelist willing to follow through the implications of his set-up.

Nic Clarke lives in Oxford, U.K., where she is using the remains of her PhD funding to assemble the world's largest pile of books-to-be-read. She also reviews for SFX and Vector, and spends too much time wittering on at Eve's Alexandria.