(It's so silly that I don't write about books more often, since my gig at eMusic audiobooks should in theory complement this kind of writing like my music commentary here complements my published music reviews.)
Rereading The Secret Agent proved disappointing. Wonder it inspires, but it's a labored wonder, strenuously earned, like Joan Crawford in her MGM films. When he wants to create portent and delineate the Deep Mysteries he lapses into a ponderousness of expression that gives the lie to partisans ready to defend the superiority of his secondhand English. Like Henry James he wrote around his weaknesses. So many aspects of human behavior remained foreign to him that he invented these fabulous structural music boxes that played odd dulcet-hued melodies with unexpected dissonances that eventually wear out their welcome. James however always attempted to unravel the figure in the carpet, as it were. He wasn't creating mystery -- he was solving one. James understood his characters more than the reader, so his endings seem ambiguous only at first (remember The Portrait of a Lady or The Golden Bowl) because we haven't untangled his subtleties. Perhaps that's why James stayed a genuine, wary fan of Conrad's, on one hand praising him in one of his last essays as one of the best of the younger generation (Conrad was well in his forties) and on the other praising Chance as an improvement over Under Western Eyes, The Secret Agent, and Nostromo, or, as he referred to them, the "three or four impossibilities, wastes of desolation." That Chance itself is an attenuated parody of those three superior novels makes the criticism especially obtuse (and Conrad's only major best-seller, as obtuse as James' own commercial bombs The Wings of the Dove and The Ambassadors). But James, as usual, hangs fire, exquisitely: the novel's predicatment, he writes, "was not imposed rather than invoked, was not the effect of a challenge from without, but that of a mystic impulse from within."
In Conrad there's a sense in which he reveled in the phantasmagorical; he sees ever more complex figures in the Jamesian carpet, most of which fail to cohere into patterns. Nostromo is a masterpiece of atmospherics and suggestion, even though its characters' motives are writ large; the boldness with which he sketches, say, Martin Decoud's idealism fails to account for the murkiness of the caesuras into which the reader tumbles (reading even the best Conrad is like walking into a familiar swamp and still oblivious to the quicksand you've almost drowned in before). It's almost as if Conrad tries to elevate stories that are essentially pulp, and was working in the wrong genre. Hitchcock's adaptation of The Secret Agent (as Saboteur) cuts the novel to size yet uses Stevie's death for non-exploitative effects in a genre known, even in the thirties, for using children as props to be exploited.