Mantega was well into his stride by now.

‘I did in fact tell my wife when I returned from work that night, but she may well not have been listening to me. Such is often the case. I’ll remind her of what happened as soon as I get home. If it comes to her making a sworn testimony in the future, I’m sure that her story will tally with mine.’

‘I’m sure it will,’ said Zen drily. ‘And she will probably deny ever having spoken to my subordinate. All right, you may go.’

Mantega frowned and stood up, shrugging awkwardly.

‘I’ve told you everything I know,’ he said in a defensive tone.

‘You’ve been a model witness,’ Zen returned. ‘In fact I shall hold you up as an example to the people I have still to question, some of whom may be less helpful. “Why can’t you be as co-operative as Signor Mantega?” I shall say. “There’s a man who’s not afraid to tell me everything he knows.”’

Mantega seemed about to say something for a moment, but then Natale Arnone came in and escorted him out. Zen went over to the window and stood looking down until the notary emerged on to the street. When Mantega was about ten metres off, one of the officers that Zen had detached from the elite Digos anti-terrorist squad got out of a parked car and started to follow. His companion started the car and drove ahead to take the point position.

Zen’s pro tem transfer to his current post as chief of police for the province of Cosenza had come about purely as a matter of chance, and had not promised — still less delivered, until a few days ago — the slightest challenge to his professional skills. A new bureaucratic entity had appeared on the map of Italy: the provincia di Crotone, carved out of the neighbouring provinces of Cosenza and Catanzaro.