SUMMER READING ISSUE : The Underbelly of the Literary Life : NOVEL : LADY WITH A LAPTOP,<i> By D. M. Thomas (Carroll & Graf: $22; 246 pp.)</i>

D. M. Thomas, the distinguished author of “The White Hotel,” has given himself a lighthearted vacation here and allowed himself a lot of fun. Underneath all the lofty thoughts, there’s a low and crummy side to the writing life, and that’s what Thomas has taken as his subject.

Simon, a ragingly unsuccessful novelist, has taken a short summer gig as a creative writing teacher at a low-rent, New Age conference on a Greek island no one’s ever heard of. It’s the kind of place you sign up for, dreaming of azure seas and gleaming stucco and sleek nude bodies on the beach, but when you get there the humidity is awful, the plumbing is on the fritz, the mosquitoes are thriving and the nude bodies on the beach are slack, white and altogether depressing.

Still, Simon is lucky to have any job at all. The poor guy is barely holding on by a thread. He has a part-time teaching job back in England, his third wife is getting ready to throw him out, his last novel sank like a stone, his current novel is not exactly a hit with either his editor or his agent, and if Simon had a realistic bone in his tired middle-aged body, he’d know the gig was up.

Luckily or unluckily, he doesn’t have a clue. Simon is the kind of writer you see everywhere, full of secondhand charm and madly bogus talent, sleeping with his female students or at least giving it the old college try, getting by on raffish charm, combing his hair down over his hairline, quoting the poetry of Rupert Brooke, using every shopworn, hackneyed phrase in the book to come off as an artist. He may not convince everyone--or anyone--but he’s fairly good at convincing himself.

Oh, it’s a terrible life out there at the summer writing conference! The staff at this hellhole is full of New Age claptrap (plus, they yearn openly for Tim O’Brien, who was such a hit last year and whose students were so crazy about him). The food is vegetarian and inedible. The rooms are stuffy, the aforementioned plumbing disgusting--although everyone tries to paint the entire experience as rustic and picturesque.

And the students! It’s enough to make a grown novelist cry. They’re broken figures from all over the world--Russia to New Zealand to America to England, longing for a couple of weeks of literary inspiration. None of them are professional writers (that we know of), and with a couple of exceptions they can’t write their way out of a literary paper bag. Simon is only too aware of this and he writes down thumbnail descriptions of them all (“Angus MacDuff . . . Red-faced, large. Wobbly jowls. Pompous and pontificating. Medieval historian. Talks nonstop. Plummy Eng. Voice though Scot. Writes poetry but has brought none, can’t imagine the stuff he writes. Purple cravat. Gay?”).

Of course, Simon manages to leave his notebook out where his students will find it. Oh, well.

In fact, there isn’t a single self-destructive gaffe that Simon manages to avoid. He goes after every breathing female on the island, touchingly sure of his aging charms. The one thing you can say about him is that he’s not picky. The little adultery isn’t too important in the great scheme of things, but Simon is a notorious motor-mouth; he blabs and blabs about every flirtation and writes indiscreet, gossipy letters and says mean things and keeps on pestering females to sleep with him. The absolute last thing on Earth he wants to do is work.

He puts off his class with dopey literary games: If you were a vegetable, which one would you be? Or a city, which one would you be? Then he puts his class to work on a freaky collaborative narrative that bears a shadowy resemblance to the weird communal life they’re all living on this island. His students, more disgusted day by day, fall away like flies.

Meanwhile, there’s a mysterious death on the island. . . .

Over on the next island, Ruth Rendell is doing real work with enthusiastic students and making an actual living at literature. But the world of books is buttressed by squadrons of has-been second-rate pretenders like Simon, depending on worn-out charm as they go on seducing instead of writing. We can’t get mad at them. They’re the backbone of the agency! Thomas lets us look at Simon--and that whole scruffy world--with real, if grudging, affection.