IN THE OXFORD BROTHERHOOD by Guillermo Martinez (Little Brown, £16.99) “G,” an Argentinian mathematics student in Oxford in 1994, is drawn into a deadly mystery through his mentor’s involvement in an academic society of Lewis Carroll admirers.

A young researcher claims to have made an astonishing discovery concerning one of the great mysteries of Carroll’s life. It’s the question which has overshadowed study of the author of the Alice books since the 1950s — the nature of his relationship with little girls, which to modern sensibilities is highly troubling.

When the researcher almost dies in a suspicious accident, G must uncover the truth of puzzles old and new to prevent further bloodshed.

A well-researched literary thriller, dripping with Oxonian atmosphere, this is also an absorbing detective story.

Repentance by Eloisa Diaz (Weidenfeld & Nicolson, £13.99) is the debut novel of a Spanish author of Argentinian parentage.

Writing in English, she sets the novel in the Buenos Aires of the 1980s dictatorship and of the supposed democracy of 2001, where disillusioned police Inspector Alzada has tried to keep his head down through all the political changes despite his left-wing youth.

His own family has suffered as others have, and he is determined they won’t suffer again. But when he is handed the case of a missing woman belonging to one of the city’s richest families, his see-no-evil strategy may no longer be sustainable. Perhaps it’s time for Alvarez to make amends to his conscience.

This superbly written political conspiracy thriller shuns both sentimentality and cynicism.

Powder Smoke by Andrew Martin (Corsair, £16.99) is the 10th book in the series about 1920s railway police detective Jim Stringer of York.

This time he becomes entangled with a love triangle between a film producer, a bewitching actress and the hot-headed star of a sharpshooting show. The moment he meets them, Jim knows their relationship can only end in violence.

There is a depth of thought and feeling to Martin’s work in this exceptional series, which is heightened by a dry humour and an evocative mastery of his settings.

A quarter of a century ago, as Shadow of a  Doubt by Michelle Davies (Orion, £8.99) begins, nine-year-old Cara has been taken from her family home to a psychiatric unit and never sees her parents again. A sloppy police investigation has concluded that she was responsible for her younger brother’s death.

Despite her stubborn insistence that he was killed by a poltergeist named Limey Stan, she was eventually transferred to the care of loving foster parents who helped her rebuild a life.

Now living and working in Essex under a false name, she has never been back to her home town, where she is still remembered as a monster.

Then comes a summons to the reading of her mother’s will and perhaps a last slim chance of convincing the world of her innocence.

Davies combines top-class suspense plotting with a heart-breaking account of what happens when children are seen but not heard.