It begins on one of Rome's least-known hills, the Aventino,
in the public piazza fronting the mansion of the Knights of
Malta. There a curious keyhole to the knights' estate
reveals an astonishing view, a direct line across the Tiber
to the dome of St. Peters in the distance.
For seven-year-old Alessio Bramante the act of peeking
through the keyhole on his way to school each day is a
ritual, a way of establishing a bond with his difficult,
distant father, one of Rome's most famous archaeologists,
Giorgio Bramante. Then one day, after an unexpected visit
to one of Giorgio's underground excavations, Alessio
disappears. A group of students who had slipped into the
site, an ancient Mithraic temple, attract the blame. A
tragedy occurs. Alessio is never found, and it's his father
who goes to jail.
Fourteen years later, in an arcane shrine by the Tiber
known as the Little Museum of Purgatory, a tee-shirt
belonging to Bramante’s son begins to show fresh
bloodstains. No one can understand how the marks have
appeared behind the glass.
Soon it becomes apparent that the newly-released Giorgio
Bramante is bent upon a vicious and terrifying revenge on
all those he blames for the loss of his son, and numbers
Inspector Leo Falcone, a member of the original
investigating team, among his targets. In the depths of the
labyrinth he knows better than any man, a distraught father
seeks his vengeance against those he hates.
Nic Costa, watching Falcone move relentlessly into the
man’s deadly grip, realises the answer to the deadly
present must lie in solving a cold case that, like the
forgotten Alessio Bramante, has long been regarded as dead
and buried for good.