Juliàn is a former inmate of a Nazi concentration camp,

obsessed with a past that no longer mattered to anyone, yet of which he could not forget a single day

.
On the threshold of old age, he travels to Spain after learning that a group of Nazi war criminals has taken refuge on the Costa Blanca.
He is driven by a profound hatred for these "dying monsters," by the desire to instill the very fear and suffering he witnessed and endured in the camp:

I had been left behind, trapped in my own world, with my hatreds, my friends, and my enemies

.
His path crosses that of Sandra, a pregnant woman in her twenties, uncertain and confused about the direction her life should take.
To the aged Juliàn, Sandra appears as the embodiment of the present and the future—realms he has never truly known, consumed as he was by a far stronger sentiment: hatred, and thus the past.

Her hair had various shades ranging from red to black, long on one side and shorter on the other.
She also wore a small nose ring.
Her eyes were somewhere between green and brown, and she had an aquiline nose.
The sunlight striking her face gave her gaze a faintly ironic air

.
An encounter between two such disparate lives was made possible because Sandra had been taken in by an octogenarian Nazi couple, who, deep down, had been charmed by the girl in the very same way Juliàn was.
With growing conviction, Sandra assists Juliàn in his investigation into this ring of criminals. In truth, it gradually becomes apparent that these former Nazis are themselves unhappy old men, locked in their own fantasies of power and youth, trapped in a web of relationships dominated by abuse and even deceit.
The futility of hatred becomes increasingly evident to Juliàn, not least because he realizes that his obsession could place the young woman in grave danger.
He finally understands that there are things far more important than constantly returning to the past.
He at last makes peace with his concentration camp ordeal, to the point of choosing to stay in a retirement home where two elderly Nazis have also found shelter.
For Sandra, on the other hand, the events in which she has become entangled propel her into adulthood, leading her to realize that her life’s purpose is to provide a peaceful existence for the child she carries.
All she is left with is the memory of her love for a young, alleged Nazi who saved her life.
There remains, in some way, an unresolved mystery—something unfinished that she may well carry within her, once again ushering in that fate of perpetual return to the past that had once been Juliàn's.

The theme of Nazism, viewed from the perspectives of both tormentor and victim, serves as an opportunity to examine the relationship between past and present, as well as the communication breakdown between generations—a gulf that can only be bridged through "doing" (Juliàn and Sandra coming together in their investigation into the criminal ring) rather than "telling," that is, the narration of lived experience.
Yet there is something more to this novel.
There is a sense of contrast between the certainty of the old and the uncertainty of the young (Juliàn is as monotonous in his hatred as Sandra is fresh in her naivety), a conflict emblematic of an epochal transition, much like our own historical moment.
In this sense, it is telling that Sandra's adulthood begins in a state of suspension that leaves the novel open-ended: what will become of Sandra and her life?

The story is told through two alternating voices (Juliàn and Sandra), a literary device that renders the narrative redundant and repetitive.
The plot, purporting to be that of a detective investigation, is devoid of incident and narrative twists.
The setting is so sparse that it could easily be any generic tourist resort, just as the characters remain thinly sketched, despite confronting ethically and existentially complex themes.

Why skip it? It is tedious and trite.

The Scent of Lemon Leaves