Evelyn Waugh's sense of humour always tended towards viciousness. In the Sword Of Honour trilogy that element of cruelty and his often malicious delight in other people's humiliation is made decidedly apparent.

Ostensibly the story of Waugh's own war, the trilogy moves at a stately pace, from the build up to conflict, to an early Dad's Army-style training camp in the south of England, to the theatre of battle, first in France, then Egypt, then Cyprus and finally back to a stately dotage somewhere in the Home Counties.

In this adaptation, the three parts - Men At Arms, Officers And Gentlemen and Unconditional Surrender - are compressed into a single drama. William Boyd's screenplay has remained dutiful - almost too dutiful - to the spirit and soul of the novels - and a sour old soul it is, too.

Waugh's hero, Guy Crouchback, volunteers immediately once war has been declared. Initially, he's told he's too old and then parcelled off into the Halberdiers, a regiment almost entirely comprised of oddballs, lunatics, misfits and sociopaths. They run around fields, stabbing potato sacks for a while, and then depart for France, where - following a series of spectacular misunderstandings - both Guy and various other members of his regiment are declared heroes, albeit dangerous ones.

Pursuing the story of war is the inevitable story of unrequited love. Guy is recovering from the ill-effects of marriage to Virginia Troy, a waspish blonde who spends almost as much time sleeping with Guy's friends as she does boasting to him about it. In addition, Waugh's own Catholic faith is often alluded to, and there are a series of small vignettes involving military superiors so weird or malign that it's difficult to believe the war ever got fought at all.

The difficulty, both in the novels and this adaptation, is that the author's misbegotten bile seeps into everything. The oddballs are never just oddballs, they are men observed with a narrow gaze and a vengeful heart. Crouchback himself is too spotless and noble to be properly heroic, and those who oppose him too small-minded and ludicrous to be credible adversaries.

None of these flaws are helped by the casting. Daniel Craig makes an admirable job of Crouchback, but, while he seems uncomfortable in the early home-bound scenes and expansive in those during the war, one suspects that the opposite might have been true in real life. Similarly, Megan Dodds, as Virginia, is no more and no less than an irritating society blonde. True, Waugh's women are often difficult to like - or even to believe in - but it is still possible, as Kristin Scott Thomas proved in A Handful Of Dust, to find some level of empathy and pathos in their lives. Guy's obsession for Virginia seems inexplicably foolish when aimed at an actress with a face like a flounder and a talent to match. When she does finally die, it comes as nothing but a relief.

Boyd has done an admirable job of turning three long, baggy books into three hours of television drama. It is not his fault if Waugh's world view seeps too biliously through the pictures, or if one of the central actors has been drastically miscast.

All in all, the adaptation has a faint whiff of school text about it - solid, workmanlike, informative - and probably not something you would naturally grow fond of.