Oh lord, where are you? In her new work, Muriel Spark imagines what became of Lord Lucan after he disappeared. A S Byatt on the pure wickedness of one of Britain's most respected living novelists

Aiding and Abetting

Muriel Spark <em>Viking, 182pp, £12.99 </em>

ISBN 0670894281

Muriel Spark has always specialised in frauds, confidence tricksters, major and minor demons and deceivers. Her characters try to take charge of their own fates, destinies and stories, and are foiled by the novelist, standing in for God - for all her wicked tales take place against a background of absolute good and evil.

In Aiding and Abetting, the Paris-based psychoanalyst Hildegard Wolf receives a client who claims to have sold his soul to the devil. He is, he says, the missing Lord Lucan, now officially dead, and suspected of the murder of his children's nanny, whom he mistook for his wife. Hildegard already has a client who says he is Lord Lucan. One is an imitation, a fraud. Hildegard herself is a fraud, wanted by Interpol. She is really Beate Pappenheim, who faked stigmatic miracles with her own menstrual haemorrhages, and relieved many credulous believers of a lot of money. She may also have accidentally worked a few miracles or cures. Her method is to tell patients her own story (but not the true story of the fakery) and not to let them tell theirs until they are desperate to do so. In certain lights, psychoanalysis is a fake, or parodic, form of confession. It is controlled storytelling, like Spark's novels.

The brief and apparently exiguous plot of Aiding and Abetting moves in an elegant and superficially heartless counterpoint. Hildegard and one or both of the Lucans have "blood on their hands". Like many of Spark's characters, they are concerned with the movement of filthy lucre, the invisible earthly powers of bank drafts and payments. They repeatedly have to disguise themselves and disappear off the face of the earth. Lucan is a compulsive gambler, and believes in "destiny" or "fate". It was his wife's destiny to be murdered because he could not pay his gambling debts (presumably having misinterpreted the movements of hazard or chance). He hears voices. He is a killer and a blackmailer - and boring, the novel, as well as Hildegard, asserts. Hildegard, although a fraud, is a would-be healer. She does not have a husband, but does have a lover who loves her, a French maker of fake antique furniture. Lucan bears some relation to the terrifying heroine of The Driver's Seat, who goes to Naples to organise her own murder and sniff out her own murderer.

Hildegard/Beate is a normal human cheat, a sinner as we all are. Her blood is her own, neither Christ's nor the nanny's.

The novel, on one level so simple and slight, is full of wicked tricks and near-blasphemous religious jokes. I think that Spark had fun with the title, which is, on the surface, about the network of "aiders and abetters" who are shown as having funded the fugitive Lucan. Aid is what Hildegard offers, and is a Christian concept. Abetting contains the idea of betting, gambling, wickedness. There is a lot of very gruesome play with the symbolism - and the reality - of blood. One of the Lucans talks about the nanny's blood seeping out of the mail sack. The other is horrified. Beate's menstrual blood is used to fake Christ's blood, which was shed from real wounds for the salvation of humanity. Beate had a friendly make-up expert who faked her wounds, whereas both Lucans have undergone plastic surgery to disguise themselves.

Lucan's favourite and invariable meal is smoked salmon and lamb chops. The fish - I am almost sure that Spark intends us to notice - is one of the symbols of the Saviour. The chop is the chop, the bloody meat, chopped up, although the Christian faith, as an endearing African doctor remarks, entails the belief that we are all washed white in the blood of the lamb. Hildegard sees Lucan's nature as "subdued to what it works in/Like the dyer's hand", and what he works in is blood. She also sees him in Shakespearean terms as "a mere anatomy, a mountebank . . . a living dead man". Again, this is a ghastly parody of Christ, who is the true living dead man. And Hildegard is a benign parody of the same thing. There is something Faustian about this Lucan's banal wanderings. He does not have the imagination to say "See, see where Christ's blood streams in the firmament", but Spark implies it for him. Dr Karl Kanzia Jacobs, the civilised African, has relations who specialise in "blood cults". The Lucans finally visit Africa where people still (in this novel) eat human flesh to absorb its virtues. The guests become the host.

At this point, the reader must ask - because of the profound uneasiness all this grim playfulness causes in the mind - what difference does it make that there is, or was, a real Lord Lucan, as there is or was a real Beate Pappenheim? There seems to be a current need, which I do not wholly understand, to make fiction run alongside fact, to insert deliberate fictions into biographies, to write novels about real people who lived. Some of this is because of an increasing sophistication about how we make up real people - lovers, friends, parents - and, even more, celebrities whose paradigmatic blisses and disasters we read about with such pleasure in the press. Princess Di is everyone's and no one's fairy tale and tragedy, but her life is a secret we come back to again and again because we know so much, and yet know nothing essential to imagine her, without making her up.

Spark, as usual, has gone for the jugular of this problem. (Hildegard is called Wolf, don't forget. There are wolves and lambs and wolves in sheep's clothing in this story.) She has chosen a boring person who is interesting because he (almost certainly) committed a real crime, a real sin, and who has since been a mystery in his banality, in the imagination that has been expended on him. Part of the problem with all this is that he may not be dead. He may be sitting in an aeroplane somewhere turning the pages of Aiding and Abetting. I still cannot work out what kind of frisson the reader - or, for that matter, the writer - of this wicked story gets from that. What is truth? asked jesting Pilate. Does it matter? I think that Spark believes it does. Herman Melville said of Moby Dick: "I have written a wicked book and feel as spotless as a lamb." She might, or might not, say the same.