The Fifth Seal

Original title: Il quinto sigillo

Author: Cossu, Davide

Publication Date:

January 2023



Original language and publisher

Italian | Newton Compton Editori

Territories Handled

Netherlands, Scandinavia, World English


Crime & Thrillers, Historical Fiction

The Fifth Seal

Original title: Il quinto sigillo

Author: Cossu, Davide


A great debut. Cossu’s writing sinks dark and seductive in the roots of history. Marcello Simoni, author of The Merchant of Cursed Books

A historic thriller with a breathtaking and overwhelming pace that portrays a Renaissance Florence that is both magnificent and livid. Charismatic characters and formidable plot twists make this novel a must read. — Matteo Strukul, author of the Medici saga

The novel is settled in Florence in 1439 during the Ecumenical Council between the Latin and Greek Churches, when Cosimo de’ Medici and Chancellor Leonardo Bruni commission Leon Battista Alberti and Tommaso Parentuccelli, to investigate a murder that took place in unsetting circumstances.

Florence, 1439. While the Ecumenical Council between the Latin and Greek Churches that is supposed to reunite Christendom is being held, a young member of the Greek delegation, Theodore Niceta, falls from the dome of Santa Maria del Fiore. Cosimo de’ Medici instructs the curial Leon Battista Alberti and his companion Tommaso Parentucellito investigate Theodore’s death. On the corpse of the young Greek, secretary to Metropolitan Bessarione, a clue is found: a gold florin, wrapped in a scroll on which the word ‘TIMEO’ is written.

Their research bring them to shed light on Theodore’s life: the young man sought the love of other men, and this led him to search for company among the guards of the Eastern Emperor. Bessarione suggests that the message might be connected to the Timeo, the dialogue in which Plato recounts the origin of the world by a divine creator, the Demiurge; the florin left on the corpse, extremely rare for its purity, came from the mint from which the other specimens were stolen. Leon Battista and Tommaso believe that the murderer hides among the Greek delegates and, with the help of the Venetian Niccolò de’ Conti, follow the victim’s trail to the taverns of the Baldracca district. There, the corpse of Isaac,commander of the Emperor’s guards, is found, and again there is a florin wrapped in a scroll over the victim.

After several encounters and unexpected revelations, Leon Battista and his two companions decipher the design of the killer: he kills his victims by following the elements that, according to the Timeo, form the universe. Suspicion converges on Michael, a novice from the convent of San Marco in whose cell the missing florins are found, but Alberti is unable to prevent the murderer from hitting his third victim, the Patriarch of Constantinople. Tommaso and de’ Conti urge Battista to continue the hunt and identify the location of the fourth murder with the help of a map. Michael attempts to kill Cosimo but is stopped by the intervention of his three companions; the novice, convinced that he is a new Demiurge, has actually been plagiarised by his master, Bernardino da Romena, mad with hatred for the Greeks, who takes his own life in a final confrontation with Leon Battista. The curial solves the case, thus allowing the happy conclusion of the council.