It’s easy in these days of plentiful bookstores and e-readers to come upon novels that are good, in the sense that they’re smart, bracing, accomplished, and maybe even innovative. Yet it’s harder to find books that are genuinely delightful — honest without being grim, funny without being shallow, romantic without being syrupy.

For a long time, I’d avoided reading Dodie Smith’s I Capture the Castle because it was rumored to be one such book, and I wanted to save it for a rainy day. A few weeks ago, that rainy day arrived and I opened the copy I’d bought at a small used bookstore on Cape Cod.

I Capture the Castle, which was a bestseller in the 1950s and was recently re-issued thanks to its passionate fanbase, is something of a cult classic. Author Dodie Smith is perhaps known best for kid-classic 101 Dalmatians, but this her most-loved work, and the new edition has a blurb from JK Rowling right on the cover.

The novel pays obvious homage to many a literary source, reading like a classic Austen classic marriage plot mixed with the tangled and unrequited passions of a gentler Emily Brontë. And in fact, its heroines, diarist narrator Cassandra Mortmain and her sister Rose, are self-described “Austen-Brontë girls” who argue about which beloved author is best while talking to each other late at night. They use a dressmaker’s dummy, whose voice they animate in turn, to talk to each other most candidly.

This is the kind of eccentric touch that permeates I Capture the Castle. The impoverished family of the protagonists have signed a long-term lease for the titular castle, a bona fide one with a real moat and “a high, round tower …on a little hill.” As the characters travel back and forth to the village, the tone almost reads like an Agatha Christie novel without a single dead body — the only casualties being the young hearts that break all over the place.

The engine of the plot is the love life of the beautiful Rose, an older sister in the tradition of Austen’s Jane Bennet — she’s self-conscious about her role as a stunner who could improve her family’s pitiful fortunes with a good match, but she may be a little too eager to secure a wealthy man. The rest of the Mortmain family consists of stepmother Topaz, who is a famous model and likes walking under the moonlight in nothing but boots, brother Thomas, and Stephen, the hired hand/adopted brother type, who’s both notably handsome and notably devoted to Cassandra. Cassandra endeavors to be “brisk” with him to warn him off said devotion, but fails since she is naturally gregarious.

The patriarch, Mortmain, has created a single work of literary genius that he’s yet to follow up. “Sometimes the abyss yawns very attractively,” he admits at one point, explaining in part his years of reading detective novels instead of writing. His great work, Jacob Wrestling, gives the characters a chance to gently argue about the value of complicated modernism, a discussion is a great pleasure to encounter. And indeed, though I Capture the Castle is a throwback to a pre-modern style, its structure — a series of diary entries — certainly throws a slight wrench into its realism. It calls attention to its own artifice, and to the fact that its narrator, Cassandra, is reliable — even wise at times — but often blind, in the tradition of many a young heroine.

As the novel progresses, the Cotton family, American-British hybrids, move into the estate on whose lands the Mortmains sit. It turns out the scions of the clan are two bachelor brothers: the very British Simon, who is to inherit, and the Americanized Neil, who dreams of ranching out West. Two girls, two boys, and infinite permutations for confusion and romance. In fact, readers might guess what’s going on in the love lives of the older characters before it becomes clear to Cassandra, thanks to the clues Dodie Smith drops in, little moments that Cassandra observes without fully processing.

Yet as Cassandra scribbles through notebook after notebook, her voice grows more assured, her observations keener and her self-knowledge more acute. Thus, even as the slightly dotty and offbeat plot points — Cassandra encounters the American boys for the first time while she’s in the bath, and there’s a memorable incident involving a closetful of old furs and a chase through the countryside — showcase Smith’s comic imagination, the heart of the book is Cassandra’s growth as a writer and person, as she strives to “capture” her family’s life, the pang of young love, and the frustrations particular to a dreamer and writer. “My imagination longs to dash ahead and plan developments,” she writes. “But I have noticed that when things happen in one’s imaginings, they never happen in one’s life, so I am curbing myself.”

“How I wish I lived in a Jane Austen novel!” Cassandra writes at one point, but her story’s ending is very different from her idol’s tidy wrap-ups. The final pages are bittersweet, but perfect in their own way as the heroine learns about the secondary and tertiary perils — and simultaneous richness — of a devotion that isn’t returned. The result is as radiant and melancholy and ephemeral as a late-summer sunset, with all its implications for our lives and destinies. “Perhaps he finds beauty saddening — I do myself sometimes,” Cassandra writes of a character she cares for. “Once when I was quite little I asked father why this was and he explained that it was due to our knowledge of beauty’s evanescence, which reminds us that we ourselves shall die. Then he said I was probably too young to understand him; but I understood perfectly.”