Long-time fans of the writer are well used by now to the mature McEwan, whose novels now come with bells and whistles. Aside from being replete with great comic set-pieces, his most recent novel, Solar, is fussilly but accessibly intelligent about melting ice-caps and the global climate outlook.

So, bells and whistles. You get a complete fish soup recipe in Saturday and in the middle of this new one, Sweet Tooth, readers are treated - whether they like it or not - to a mathematical problem whose game of probability quickly lost this reader.

Fortunately, to abosorb the narrative it wasn't necessary to understand the business of "which door do you open in the three hotel doors?," the trope at the centre of the maths problem in question. You could go out and wash your hair, or have a pint while that particular passage is going on and you wouldn't miss an awful lot in truth.

The Comfort of Strangers showed that he could do spooky very well indeed, but that was two decades ago. On the other hand, he does spooks in this new 320-page novel, which faithfully evokes the Ted Heath years of inflation, petrol shortages, strikes, doom and gloom.

The story is told by the attractive Cambridge maths graduate Serena Frome who is recruited to work for MI5, through her affair with an elderly, married Cambridge don who has also been working for the organisation. He cuts out of the relationship suddenly and mysteriously and dies shortly afterwards.

Therafter, Serena is assigned the task of luring a vaguely promising young fiction writer and journalist, Tom Haley, who seems to have somewhat reactionary tendencies, going against the flow of the usual pro-Soviet Russia intelligentsia.

The plan is that Haley and the other writers recruited unwittingly in the clandestine operation known as `Sweet Tooth' will not know their true benefactors. A front organisation called Writers Unpenned sets the thing in motion.

Although he is rightly suspicious at first, Tom is led to believe that a well-meaning real life foundation is funding him. The elaborate wheeze is reasonably subtle, the writers are not told what to write. But their works will ostensibly help to win hearts against similar propaganda initiatives waged by the Soviet empire, as the Cold War creeps inexorably onwards, like a slow glacier.

Then, Serena falls in love with Tom, which is the last thing her sinister employers want. And, counter to expectations, he wins a prize for a novella whose morality tale seems to portray capitalism as something doomed to end in apocalyptic meltdown. The press naturally gives prominent notice to the new prize-winning author, before they cotton on to a hell of a lot more too.

Born to thrill us no matter what he does, McEwan keeps the narrative engine well primed, but he could have kept the story shorter and more taut.

Paddy Kehoe