There’s never been a better novelist of ideas than Dostoevsky, and there’s never been a better expression of the power of ideas—how they might not just drive action but consume a soul—than an exchange from his 1872 novel Demons. To set the scene: Kirillov, one of Dostoevsky’s saintly, nihilistic madmen, has decided to commit suicide; only by killing himself, he reasons (though that verb doesn’t quite fit), can he prove his absolute and God-like freedom. His friend, the revolutionary Pyotr Verkhovensky, decides to use Kirillov’s suicide for his own political ends, but not before making this remark: “I’ve never understood a thing about your theory, but I do know that you didn’t make it up for us, and so you’ll carry it out without us. I also know that it was not you who ate the idea, but the idea that ate you.”

It was the idea that ate you: what a perfect and horrifying description of how a theory about God or suffering or politics can take on an agency and power all its own. We create ideas, and then, if we’re not careful, they consume us. You can appreciate this truth whatever your political leaning. The right stoked racial resentment, the left says, and now it’s winning by Trump-style nativism. The left worshiped diversity and tolerance, the right says, and now it’s being eaten alive by political correctness. The left and right refused to compromise, the centrists say, and now they both find themselves locked in interminable conflict. Ideology is like Frankenstein’s monster: you think you’re its master until, all of a sudden, it has its hands around your throat.

Two excellent recent novels, Karan Mahajan’s The Association of Small Bombs (Viking, $26, 288 pp.) and Jonathan Lee’s High Dive (Knopf, $26.95, 336 pp.), tap the same vein that Dostoevsky did more than a century ago. Both novels center on historical acts of ideological extremism: in Mahajan’s case, the 1996 bombing of a New Delhi market by Kashmiri separatists; in Lee’s case, the 1984 attempted assassination of Margaret Thatcher, when members of the IRA planted a bomb in the Grand Hotel in Brighton weeks before a meeting of the Conservative Party. And both novels, like Dostoevsky’s, stage chilling debates about the ethics and efficacy of violent political action. In The Association of Small Bombs, Tauqeer, a radicalized former software engineer, argues that larger attacks—like the one on September 11—are actually more merciful than smaller ones: “I think the small bombs that we hear about all the time, that go off in unknown markets, killing five or six, are worse. They concentrate the pain on the lives of a few. Better to kill generously rather than stingily.” In High Dive, Dan, the IRA agent who plants the bomb, justifies his actions to himself: “He’d had second thoughts, third thoughts, fourth thoughts. But doubt was a disease, a sentimental curse, and in the long run his actions would save lives. A new prime minister. Politicians seeing they were vulnerable on their own doorstep. Seeing that this war could cut both ways. The beginning of the end of apathy, maybe. The start of an understanding.”

There is a purity and easefulness that arises when ideology takes over, when the idea has eaten us whole. “As a master terrorist”—such an unnerving phrase—Tauqeer “no longer saw the strangeness of what he did or how he talked about killing.” Likewise, Dan admires the simplicity that violence affords: “The truth was that on an operation you felt clean of guilt and will. It was day-to-day Belfast life that made you dirty.”

What makes these two novels so troubling is precisely how easy it is for their characters to fall into terrorism. Yes, there are personal and political reasons. In The Association of Small Bombs, Shockie, the man who designs and plants the bomb in New Delhi, is from Kashmir, a land that has suffered greatly since the Partition of India in 1947. In High Dive, Dan’s father died at a demonstration and his brother was shot on Bloody Sunday, leaving Dan to wonder, “What do you do when the people making the rules aren’t interested in fairness? When they choose who to protect based on religion, race, history? The police are scum. People who join the police are scum.” But neither Dan nor Shockie is by nature particularly political or especially violent. Things happen, and they just kind of fall into terrorism—because it’s convenient, because it offers purpose, because it’s exhilarating. A life stripped of will, guilt, and strangeness: that is what motivates the Kashmiri separatist and the IRA agent, the Muslim and the Catholic.

WHEN WRITING ABOUT an historical event like a bombing, the novelist is faced with a structural problem: what to do with chronology. We already know that Shockie’s bomb will go off and that Dan’s will, too. We already know—or easily could find out—how many will die in New Delhi (thirteen) and in Brighton (five), and we already know that Margaret Thatcher won’t be one of the victims. So how to structure the novel when we already know where it’s headed?

In The Secret Agent, Joseph Conrad’s 1907 novel about an anarchist plot to blow up the Greenwich Observatory, he chose to fracture the chronology: the explosion happens, and then we jump back, without explanation or context, to an earlier point. Conrad’s temporal juddering makes thematic sense. The Observatory measured standard time. When it is attacked, so too is the standard time of narrative, the orderly procession of one event after another.

Mahajan starts with the bombing and then moves forward, training our eyes not on the explosion but on its aftermath. The novel begins like this: “The bombing, for which Mr. and Mrs. Khurana were not present, was a flat, percussive event that began under the bonnet of a parked white Maruti 800, though of course that detail, that detail about the car, could only be confirmed later. A good bombing begins everywhere at once.”

That last aphoristic sentence is typical of the novel in two respects. First, it displays Mahajan’s skillful compression, his ability to write sentences that you want to read out loud and perhaps memorize: “You destroy a city with the material it conveniently provides”; “For every decision there were a million others he could have made. For every India, a Pakistan of possibilities”; “A bomb was a child. A tantrum directed at all things.” This tendency toward aphorism is usually effective, though there are instances when Mahajan seems to be straining. The best writers, however quotable, don’t write sentences in which you can almost hear the writer patting himself on the back for his own quotability—sentences like this one: “...it was as if he were sitting at a ceremonial fire, fanning a tragedy toward himself.”

The claim that “a good bombing begins everywhere at once” also suggests the deep interconnectedness of the novel’s many characters, places, and moments. An act of terrorism is, of course, a sower of chaos. But it also creates a sort of order—or, at least, it reveals connections between hitherto unconnected parties. We learn that Mr. and Mrs. Khurana, mentioned without context in the first sentence, lose two sons in the blast, Tushar and Nakul. These two boys were in the market with their friend Mansoor. Mansoor, years later, becomes the mentee of Ayub, a charismatic and nonviolent defender of the rights of accused terrorists. Ayub eventually becomes disillusioned, joins a group of militants that involves Shockie, the original bomber (still with me?), and takes part in a bombing himself—an action that results in the arrest of Mansoor.

This Dickensian intertwining of plots and characters is impressively done, and it serves a serious purpose: to remind us that terrorists don’t come out of nowhere. Rather, they emerge from complex lives and histories of their own. The novel’s title comes from a support group that Mr. and Mrs. Khurana create for those affected by small acts of terrorism. Terrorism, Mahajan suggests, is a phenomenon that arises in response to the fracturing of community. The Kashmiri don’t feel politically recognized, and so they lash out; this lashing out breaks up another community, this one in New Delhi; then, out of the wreckage, there forms a new community, one united by trauma. The word “jihad” doesn’t appear in The Association of Small Bombs, and that’s telling. Terrorism, in this novel, isn’t a religious problem. It’s fundamentally a social and political one.

In High Dive, Lee takes the opposite chronological approach. We begin, very briefly, with Dan’s initiation into the IRA in 1978. Then, after a chapter break, we’re in 1984 at the Grand Hotel. We know that the end is coming, though we have over three hundred pages to get there. Lee introduces us to the novel’s two major characters: Philip “Moose” Finch, the hotel’s deputy general manager, and his daughter Freya. The Grand Hotel “was all about excess,” and Moose cherishes the garishness of it all: “the warmth of opulence, the mellowing air of antiquity, the fragrance of fresh flowers.” He’s a man who likes his job and the intimacy-at-a-distance he is able to achieve with the hotel’s guests: “Hospitality involved an aspect of surface flattery but also of deep familiarity. It was a peculiar combination of density and gauze.”

Moose leads a quiet life—slightly regretful but on the whole rather contented. He isn’t the athlete and man about town that he once was, but he enjoys his work; his wife left him years ago, but he has an infatuation with a coworker; he and his daughter bicker but they also enjoy one another. Also, things are just about to get better: if the Conservative Party conference goes well—which, of course, we know it won’t—Moose thinks he’ll get a promotion. Life for Moose possesses a gentle, tempered happiness: “For to be alive, to be capable of laugher and surprise—this itself was a beautiful thing.” Lee’s prose is filled with sparks of aliveness, little moments of lyrical realism: a sleepy Moose looks at the world “through waterlogged lashes”; a minor character’s unruly hair has an “enthusiasm for adventure.”

Freya, however, is a bit at loose ends. She’s in her gap year, between school and university, and her life is filled with gaps: between where she is (Brighton) and where she wants to be (not Brighton), between who she is and who she wants to be: “she was maybe suffering from a lack of something, a smallness or thinness, a stuntedness even, like there was a higher plane of being she wasn’t reaching for.” She drinks a little, flirts a little (“She’d noticed lately that lust and boredom shared a bed”), and becomes interested in a guest named Roy Walsh.

“Roy Walsh” is actually Dan the IRA agent, a fact that we know and Freya doesn’t—one of the novel’s many painful instances of dramatic irony. When Freya looks at this slightly older man, she sees “a face with potential”: “Skiing, waterskiing, sailing, sex in water…Argentina, Botswana, Cambodia, a whole alphabet of adventure.” But of course Dan isn’t a portal to adventure; he’s the deliverer of tragedy. His arrival at the hotel doesn’t signal the possibility of another life; it signals the brute actuality of broken glass and falling ceilings. While Lee does spend some time fleshing out Dan’s backstory, the focus is on Moose and Freya—a focus that makes the long-dreaded climax almost unbearably sad.

Lee is, in a certain sense, as far from the Dostoevsky of Demons as you can get. His characters are reasonable, generally kind, thinking about the past but not tortured by it. In short, they’re British. But like Dostoevsky and like Mahajan, Lee reminds us of what happens when we allow our souls to be consumed by an idea. Dying in the rubble of the Grand, a character tries to hold on “to the private moments history so rarely records but which make up the minutes in the hours. ‘Please,’ he said, but it did not help. Someone had considered this fair.” Such are the costs of ideology trumping life.