Beneath the scorching heart of a Brazilian gold mine, a deadly secret is about to be unearthed.

A chance encounter in Rio plunges ex-police commissioner Peter Craig into a deadly game of cat and mouse amidst the scorching depths of a Brazilian gold mine.

Tasked with uncovering the source of unusually-coloured diamonds, Craig traces their origins to Horst Graben, a former adversary with a shady past and a talent for disappearing. Their paths collide in Rio, sparking Graben's suspicion and igniting a chain of events that leads to murder.

Following a trail of clues to a remote mining town, Craig finds himself entangled with the de Sá family – the mine's owners – and their captivating daughter, Alcidia. As he gets closer to the truth, danger escalates, culminating in a harrowing confrontation on the mine's perilous twenty-fourth level. Trapped in a sweltering inferno, Craig must outwit a desperate killer and unearth the secret that binds the diamonds to the mine's fate.

Reviews of Twenty-fourth Level

"An exotic setting in Brazil and, in particular, deep inside a gold mine; an escape whose mechanics are as ingeniously worked-out as even Iris Murdoch could have managed; and a completely original method of murder, the capoeirista, a macabre invention of Bahian slaves. In all, a good, intelligent thriller, with a properly villainous villain and an attractive love interest."
-- Times Literary Supplement, 1969

"Tense, all-action story played out against the dazzling life of Rio de Janeiro and the sombre mountains of the inland mining country. Diplomatic Service man investigates diamond puzzle, tangles with sinister German, and fights nightmare duel for survival deep underground. Tinglingly different.”
-- Sheffield Morning Telegraph, 1969

"The description of the great mine and its working is fascinating, but any claustrophobic is advised to skip to the rather horrifying climax on the twenty-fourth level. A really impressive first novel."
-- The Guardian, 1969

"Rio and its mining hinterland described by a Baedeker-thorough guide. Lots of excitement and some decent, old-fashioned love."
-- The Times, 1969

"Mr Benton designs his goings-on with unusual skill--there are never any moments where you long for mayhem as a relief from the interludes, or when you long for the interludes as a relief from the mayhem--and his love-interest, admittedly old-fashioned, easily triumphs over the absence of explicit bedwork. Rather moving stuff, actually, and though extensive for a thriller, it helps the narrative instead of (as so often) interfering."
-- The Sunday Times, 1969

"Capable, fast and nicely atmospheric.”
-- The Sun, 1969

"What was the secret concealed in a few strangely coloured diamonds, for which a German gold-mining engineer was ready to kill? Peter Craig, police advisor to Diplomatic Service in Brazil, unravels the bizarre threads linking the German with a beautiful, nineteen-year-old heiress. Startling climax in the deepest gallery of a mine, where two men have only their courage between them and death."
-- Evening News, 1969