Not surprisingly for a captain with 20 years’ service in the British merchant marine, Joseph Conrad revered “the ship-shape.” By this he meant a just regard for the proper placement of things and, most especially, the right arrangement of words. Though robustly competent in all sorts of practical matters and flamboyantly fastidious in his dress – Thomas Mann is his only rival in dapperness among modern writers – Conrad was no mere fussbudget. His detestation of unruliness arose from a life of dislocations, beginning with his childhood in Poland.

In addition, his temperament was exquisitely sensitive. A stern ship’s officer, he was harshest on himself; his fabled bouts of writhing on various sofas as he grappled with some turn of phrase, amid heavy groans and much gnashing of teeth, were documented by several witnesses. His exasperation with the act of writing – and writing English in particular – caused him to veer from moments of near lunacy, when some unsuccessful skirmish with a recalcitrant word reduced him to despair, to rarer instants of brimming delight at the unexpected, but inevitable, mot juste.

The English language, of which he became so great a master, provoked him to fury; he found it hopelessly “blurry.” Perhaps, in the end, the need to govern the ungovernable (the essential job description of a naval captain, after all) gives his prose its nervous sonority. Those dense but shapely sentences, with their subtle hints of jaggedness, are like no one else’s. I suspect that what drove Conrad ragingly to English – he was far more at ease in Polish or French – was the sheer “fascination of what’s difficult,” to borrow Yeats’s phrase.

The same quirk may have prompted this lover of the ship-shape to embark on an exploration of the grubbier outskirts of nihilism. In “The Secret Agent” (Oxford World Classics), first published in 1907, Conrad delineated the terrorist mind with unsettling prescience. The recent atrocities in London sent me back to Conrad’s novel, and I’ve come away from it with fresh admiration.

Conrad was no pundit. He struggled to understand the impulse to bomb-throwing, and suicide-bombing, not by recourse to ideology or socioeconomic conditions but by delving into the very souls of his characters. Chief among these is Adolf Verloc. The indolent proprietor of a back-alley shop specializing in off-color wares, Verloc is bullied into action by his handler, Mr. Vladimir, a suave man-about-town with murder in his heart who occupies some vague ambassadorial post at an unnamed embassy (given Conrad’s feelings toward imperial Russia, we can guess which one).

In a nod to Flaubert, whose “A Simple Heart” he fervently admired, Conrad subtitled the novel “A Simple Tale”; in fact, there are sly echoes of Flaubert’s story throughout the novel, most notably in the tragic account of Verloc’s wife, Winnie. Yet with its array of figures, from clueless society ladies sympathetic to anarchy to dogged police inspectors to the motley and ineffectual nihilists themselves, the story is anything but simple.

Conrad took the idea from an actual episode. On February 15, 1894, a French anarchist named Martial Bourdin made a bungled attempt to blow up the Royal Observatory in Greenwich but succeeded only in injuring himself fatally. In “The Secret Agent,” Conrad sought not merely to illumine the motives of such a crackpot but, in keeping with his famous artistic credo, “to make us see” the entire snarled web of circumstances – individual as well as societal – that led up to the act, and to see these in pungent and indelible detail.

Take one tiny example. Verloc’s shop is fitted with a bell to announce customers. This bell is more than a prop; throughout the tale it plays its own part: “The bell, hung on the door by means of a curved ribbon of steel, was difficult to circumvent. It was hopelessly cracked, but of an evening, at the slightest provocation, it clattered behind the customer with impudent virulence. It clattered; and at that signal, through the dusty glass door behind the painted deal counter, Mr. Verloc would issue hastily from the parlour at the back.”

This is but one of the descriptions by which Conrad builds up his thick, seething, palpable London of sooty facades and vertiginous alleyways, through which his anarchists and their police pursuers thread their baffled and often terrified ways. When Mrs. Verloc must take her elderly mother to an almshouse, the jolting cab ride through the dank streets becomes a sinister epic for the downtrodden. The hideous driver is a kind of Charon, and when he leaves them, there is “an air of austerity in this departure, the scrunched gravel of the drive crying out under the slowly turning wheels, the horse’s lean thighs moving with ascetic deliberation away from the light.”

In the stunted, warped, embittered character known as “The Professor,” Conrad created one of his most loathsome, and timely, figures. Motivated by vanity, this scuttling nihilist never leaves his flat without a bomb concealed in his clothes, and his hand never leaves the bulb that will detonate it. His pocket-detonator is the only thing that distinguishes him from the multitude, and he caresses it with almost sexual obsessiveness. “Exterminate! Exterminate!” is his slogan. As we follow this verminous figure through the London streets, we come to realize that it is self-hate, more than vanity, that propels him, for he is himself one of “the weak, the flabby, the silly, the cowardly, the faint of heart, and the slavish of mind” he so longs to annihilate.

Against this embodiment of catastrophe, Conrad sets the only character in the novel capable of heartfelt compassion, the half-witted brother of Mrs. Verloc. Addled, half-coherent, helpless, he alone is moved to rage and pity by the sufferings he witnesses on the London streets and, of course, he alone becomes the accidental victim of the anarchists’ muddled plot.

Conrad died on August 3, 1924. Within the same year, his friend and collaborator Ford Madox Ford published his book “Joseph Conrad: A Personal Remembrance” (out of print, but available on the Internet). This memoir – which is also one of the best books I know on the art of English prose – gives an unforgettable portrait of Conrad. Ford remarks, “The British Empire was for him the perfection of human perfections, but all its politicians, all its public officials, police, military officers of the Crown, gaolers, pilots, port admirals and policies were of an imbecility that put them in intelligence below the first lieutenant of the French navy that you could come across.” Conrad’s unshakable ideals of loyalty, of devotion to duty, never blinded him to stupidity or wickedness; lucidity was integral to being “ship-shape.”