FICTION: Red AprilBy Santiago Roncagliolo, translated by Edith Grossman Atlantic, 271pp, £12.99

VIOLENCE STALKS the pages of this bold, extraordinary thriller. It is a sophisticated work of terrifying cunning; here is a novel to make one gasp and wonder anew at the furtive extremes of human behaviour. The crimes we commit; the hurts we store in our minds, those wounds that never heal.

“Perhaps you’re right,” the commander concluded, “Perhaps this has to do with Holy Week. But not the way you think. You’re a strange guy, Chacaltana. You’re always about to hit the bull’s eye and you always miss.”

This is the most important moment in a narrative of important moments. Associate District Prosecutor Félix Chacaltana Saldivar is more than strange; he is deeply disturbed and given to laying out fresh changes of clothes for his long-dead mother.

He is also somewhat passive. When the commander insults him, Chacaltana thanks him and then wonders privately “if he should have said that”.

Peruvian writer Santiago Roncagliolo has drawn on the appalling record of the Senderista, the Sendero Luminoso or Shining Path, an ultra-left crazed Maoist cult movement given to vicious purges. The politics of Peru are presented as a murky ballet of left-wing terror and military corruption with a sub-plot in which the traditional native and religious beliefs battle in vain for survival. Every family has its sorrows and secrets and hatreds.

Roncagliolo makes clear that he has used documentary records of investigations and interrogations conducted by all sides; and that much of the action in the novel is based on events which took place in Peru during the Easter period of 2000. But this is no faction yarn; Roncagliolo has, in the character of Chacaltana, created a portrait of an individual living in a twilight zone. Given to nightmares, he appears to be preoccupied by his devotion to his mother. He shares a house with her, speaks with her and is dependent on her. Although she is dead, he doesn’t mind others, including a girl he is interested in, knowing that he considers his mother very much alive. His wife left him and he knows his colleagues regard him as a joke. Every hint of irony is brilliantly conveyed by Edith Grossman’s translation. For all the horror, it is also subtle and makes effective use of the unintentional comedy of menace:

Without knowing exactly how, the Associate District Prosecutor was allowing himself to be led to the door by the subordinate’s words. He tried to respond, but it was too late to speak.

As the novel opens he has been handed a case, to unravel the reasons behind a gruesome killing. The only clue is a hideously charred body. Chacaltana has returned to Ayacucho, his home town, after some years in Lima. His reason for coming back was to be with his dead mother. So he lives with her spirit and spends most of his time fashioning carefully mundane reports. He takes pride in them, he lives in his muddled thoughts, convinced of his clear thinking but regretful of his lack of action.

Red Aprilwon one of Spain's major literary prizes in 2006. The story is complex, but the real strength of the novel lies in Roncagliolo's superlative telling. Within sentences the shambling prosecutor rises from the pages. It is as if he is walking among us, a diffident, nervous man. One of the letters on his typewriter is missing, but he can manage – "He had a large vocabulary and could replace one term with another. He repeated to himself with satisfaction that in his lawyer's heart, a poet struggled to emerge."

Yet while Chacaltana seems a weak man, given to nausea as he examines mutilated corpses and always battling his self-doubts and his failures, a darker side bubbles just beneath the surface of his daily behaviour. He begins to become attracted to Edith, a young waitress. The courtship stumbles along. His instinct is to tidy away the unpleasant in his official reports – “husbands do not rape their wives: they fulfil conjugal duties”. Each time he meets either a policeman or a soldier, he is defeated by their sharper street-wise reading of what is actually happening.

The dialogue is well handled. In every exchange Chacaltana is presented as a fool while knowing, cynical military men, immune to the daily outrages, laugh openly in his face before resuming card games. When he is despatched to oversee an election, the local commander informs him that he is pathetic and continues: “But I understand you. You haven’t been here very long, have you? You don’t know these half-breeds. Haven’t you seen them hitting one another at the fertility fiesta? They’re violent people.”

As a sequence of horrific killings begins, each one leading the prosecutor back to the same priest, the same doctor, a sense of ritual cleverly asserts itself. There is also the religious symbolism. Roncagliolo makes use of fire and light; there is a bizarre element of sacrifice.

All the while, an increasing ambivalence pursues the characterisation of Chacaltana. Never a hero, he begins to seem more damned than merely damaged. However, he also seems to acquire a more questioning intelligence. He loses his pleasure in reports:

A real report, he concluded, could be written only by God, at least by someone with a thousand eyes and a thousand ears who could know everything.

This intelligence may be tied to his realisation that everyone he meets invariably ends up dead. Red Aprilis a study of anarchic responses. Roncagliolo remains in complete control of a hall of mirrors that is as medieval as it is modern. It is one of those narratives that ask many questions, including "how did he do that?". How indeed?

This is a dark and almost unhinged display, utterly confident, impressively restrained. Haunted, hunted Chacaltana writes reports; he is a pen-pusher, not a problem-solver. He seeks a killer, only to find it in himself.

Eileen Battersby is Literary Correspondent of The Irish Timesand is author of Second Readings: From Beckett to Black Beauty, published by Liberties Press