George Orwell seems amused in many of his photographs; his twinkling gaze laughs at those who would look at his likeness. John Mortimer peers out from the photo on the jacket of his new book, Felix in the Underworld, in a disconcertingly similar manner. His tightlipped, bemused smile and his merry eyes dwarved by oversize spectacles almost mock idle viewers of the snapshot. Best known for his many short stories and plays about the crotchety, crime-solving barrister Rumpole, Mortimer is hardly considered a literary relative of Orwell's, yet the immense entertainment value of his new book owes a debt to some very Orwellian features of the compelling, satisfying mystery.

Americans will promptly notice a British accent in Mortimer's writing. Novelist Felix Morsom inhabits a world of prawns and wireless sets and lorries painted carmine, where children do their prep every night for school and where adults have sexual connection. The distinction between a barrister and a solicitor and other niceties of the English legal system, which play a rather prominent role in the latter part of the book, can also be confusing to the uninitiated on the other side of The Pond, but no cultural barriers can mitigate the horror of the nightmarish side of London suddenly exposed one day to Felix.

Felix, who leads a tame existence churning out book after book about "frustrated middle-class lives," is unprepared to suddenly receive some vaguely threatening communications from Gavin, a shadowy character who introduces him to Miriam. Mirry avers that Felix fathered her son Ian a decade ago, and Felix, hard-pressed to disprove her case, is summarily presented with a bill for 20,000 pounds for Ian's keep from the Parental Rights and Obligations Department.

The menacing, seemingly omnipotent PROD would fit well in a book called 1997, but Felix's perplexing predicament owes as much to Kafka as to Orwell. Frustrated by the impenetrable conspiracy enmeshing him, Felix frantically threatens Gavin, his only link to the mysterious world of Mirry and PROD. Unfortunately, when a dead and mangled body surfaces in Gavin's car, Felix's wild threats make him the prime suspect in the murder investigation.

Here again Mortimer borrows a page from the Orwell oeuvre. Down and Out in Paris and London chronicles Orwell's marginal survival for a time among the London poor; Felix, too, temporarily joins the ranks of London's lower classes to escape from the police and to search for Gavin, who Felix spots alive after his purported murder. Certainly Felix's short sojourn on the London streets is well-written and memorable, but it scarcely seems central enough to the book's plot to justify the title. The time Felix spends on the streets between the murder and his subsequent arrest is quite brief, and the one friendship Felix strikes up with a fellow drifter seems gratuitous, as if a mechanism for adding another death to the slowing plot of the mystery.

Mortimer describes better Felix's normal habitat when he is not being tried for murder, the circle of literary lions who lunch and speak and tour to promote their books. The formalities of the book-touring circuit seem deliciously droll when dripping from Mortimer's pen, and the occasional appearances of Sandra Tantamount, Felix's chief rival within his publishing house, furnish a comic garnish to a sometimes somber book. Felix's hapless adventures on tour and his constant, futile pursuit of his publicist illuminate Felix's personality even as they entertain.

Much of Felix's charm comes from its wonderfully self-conscious adherence to the classic conventions of mystery novels. A few key red herrings are made painfully obvious, as are several crucial clues. A large, distinctive signet ring is referred to in detail three or four times; only a very slow-witted reader could fail to mark its significance. In the car after interviewing Mirry about Gavin's death, one policeman turns to his partner and asks significantly, in time-honored detective novel tradition, "I wonder how she knew [the murder weapon] was a spanner," since the precise murder weapon had not been divulged.

After Felix's inevitable imprisonment, publicist Brenda Bodkin continues his sleuthing just like a good Agatha Christie heroine would; her graceful conniving reawakens police interest in the case. Mortimer even indulges in the requisite bad pun or two, when Mirry speaks of being 'dead on time' or when the ever-lustful Felix fantasizes dramatically about "making his 'quietus with a bare bodkin." The solution to the mystery is not especially convoluted and veteran mystery fans will likely guess the conclusion long before the end, but in no way will this diminish their pleasure in the consistently suspenseful final chapters.

Ian, the innocent child who indirectly causes all this fuss, emerges as the center of both rationality and emotion in the novel. Existence with his flighty mother Mirry is less than satisfactory; when post-murder complications force her to leave Ian to fend for himself for a while, Ian, instead of lamenting her absence, looks forward to "a really good tidy-up" of their filthy apartment. He alone remains calm through all the turbulence of chaotic events, yet it is his plangent, intermittent requests for paternal affection that add a touching although never cloying emotional dimension to the book.

A detailed discussion of Ian's ultimate fate and parentage, of course, would reveal a key secret of the book. But the gentle presence of Ian, in the end, transforms Felix in the Underworld from an enjoyable if hackneyed yarn into something different and superior, a mystery novel with heart.