You might set a protagonist higher upon a ladder for the sole purpose of knocking it out from under him, but it's hard to imagine you doing it with such wickedly comic effect as Sam Savage has done in plotting the fall of Andrew Whittaker. "The Cry of the Sloth" -- Savage's follow-up to "Firmin," his surprise bestseller about a book-eating rat -- gathers the epistolary shards of Whittaker's crash and arranges them in a Zen garden of perfect misery.

Interspersed with rental notices for his slum properties, shopping and to-do lists, and excerpts from an impossibly bad novel involving sex fantasies, self-loathing and lawn mowers, Andrew Whittaker's letters frame a rough plot around the last-gasp efforts to save his literary journal, "Soap." ("The first to publish Sarah Burkett's harrowing travelogue 'The Toilets of Annapurna.'") Much like his efforts to save his crumbling slumpire, this is an effort so desperate on its face that you laugh at its first mention and continue to laugh long past the point of embarrassment.

With such a shaggy-dog plot and risky narrative device, Savage has set himself up for a fall as spectacular as his protagonist's. And yet, he rarely falters: Andrew Whittaker may just be the most lovably unlovable character in recent letters:

"Dear Mrs. Lipsocket,

"You have been sending me your poems off and on for four years. ... You have been the cause of broken sleep in which I dream that I am beating small animals. Faced with this, I surrender."

So goes one of Soap's acceptance letters.

Whittaker is fond, too, of defending his outrages using anagrammatic stand-ins at the local paper, in one case "Warden Hawkitter, M.D."

But as Whittaker approaches his wits' end (a short journey, comparatively), Savage allows him to stretch beyond a stock narrative unreliability and achieve a comic repose that approaches dignity: "This is all I'll be sending for a long time. I am preparing to consolidate my mind and enter a forest to live on acorns, thereby turning what's left of my life into a manageable asset."

"The Cry of the Sloth," by its close, marries melancholy and laughter so finely that it ends as a wonder. Whittaker's story could only have been tended into existence by a failed novelist (it's too funny; it hurts too much). That it has been pulled off as a marvelously slapstick tragedy says volumes about Sam Savage's talent: Turns out this late bloomer is also a repeat bloomer.

Joel Turnipseed is the author of "Baghdad Express." He lives in Minneapolis.