Actor. Comedian. Celebrity runaway. Stephen Fry has a way of saying a word like arse that is either uproariously funny or sick-making. Such a test will inform your chances of coming to love his second novel, The Hippopotamus.

Gay, celebrated celibate, left-wing actor and comedian and celebrity runaway. No one is about to ask Stephen Fry if the sometime narrator of this book is in any way autobiographical. Ted Wallace is an ageing, cantankerous unrepentantly right-wing drunk. A womaniser, failed poet and now redundant theatre critic. Behind on his alimony payments and overflowing with bile at an unjust world, Ted seeks solace in a favourite drinking hole only to meet up again with goddaughter Jane Swann, now dying (or maybe not) of leukaemia: looking "exactly as girls in the early Sixties did when they returned from visiting the abortionist".

Jane offers Ted a quite improbable sum of money to inveigle his way into Swafford Hall, country mansion of media-baron and old friend Lord Logan, to witness at first hand the bizarre phenomena - the miracles - apparently going on there. And never being a man to turn down a quite improbable sum of money, Ted Wallace is swiftly writing to sensitive godson David, inviting himself to an open-ended visit on the pretence of penning a family history.

Not a lot happens in Fry's book. Indeed, much of its 363 pages are taken up less with events than Ted's sour, whisky-sodden - and filthy - reflections on poetry, new technology, religion and the like. The author populates the sprawling house with a grisly assortment of eccentrics, from David's brother, the earthy (read: thick) Simon and the almost infeasibly dull local writer Malcolm Whiting, to the gamekeeper's deformed daughter and Oliver, the outrageously queer ex-priest who harbours somewhat less than holy lusts for the outrageously pretty adolescent David.

The Hippopotamus could have "POLITICALLY INCORRECT" stamped across the edge of its pages. From Ted's philosophising and bedding to the latter half's extraordinary sequence sexual couplings (there is, it seems, more than one way to ride a horse), this is a veritable catalogue of depravity. And also extremely funny; this is a funny book without being sniggeringly comic. This is outrageous without the silliness. This is Tom Sharpe for grown-ups. The plot, for what it's worth, has something to do with faith healing and teenage self-delusion. How such a barbarous old hippopotamus as Ted Wallace can eventually emerge as almost a hero must say something, as does a final note of off-centre sadness that infects proceedings; Fry clearly doesn't find everything hysterically funny.

Read this novel (it's most definitely worth that) and along the way - Will Self-like - increase your word power without recourse to the Readers Digest: "ataractic", "soterial", "prefectorial", "boxwallah" all get an airing. And at least no one can blame Fry for misspelling "phenonmena" on the back cover.