A Season for the Dead by David Hewson
Stefano's left arm, the one holding the weapon, swept the table, swept everything on it . . . She was quiet, waiting, which was, his eyes seemed to say, what he wanted. Then Stefano lifted up the bag to the height of the desk, turned it upside down, let the contents fall on the table and said, 'The blood of the martyrs is the seed of the Church.'
Whilst Sara Farnese pours over ancient texts in the silent Vatican reading room, a brutal murder is taking place in a nearby church. Then suddenly a crazed man enters the Vatican carrying a bloodied bag. He walks up to Sara's desk. He has something he would like her to see . . .
Soon Sara is inextricably linked to a series of horrific and cunning murders, each one representative of the death of a martyr of the Church. Into this climate enter Detectives Costa and Rossi, enlisted to track down the killer, and to protect Sara from the horrors he is capable of. It seems that at any time she could be the next chosen sacrifice . . .