A dull ringing from the embedded rails announced the arrival of an elderly tram, swaying and nodding its way out of the tunnel burrowed under the Monte di Dio. Zen folded up his newspaper and waited patiently while it trundled through the massed traffic towards him, its bell jingling plaintively. Ten minutes later, the tram deposited him in Piazza del Carmino, outside one of the main entrances to the port area. Zen walked in through the open gates, nodding perfunctorily to the armed guard, who sketched a salute.

He crossed the concrete yard inside the gates and turned right towards the four-storey building which housed the detachment of the Polizia dello Stato responsible for law enforcement within the port area. Most of this enclave, as well as the neighbouring parts of the city centre, had been flattened by both Allied and German bombing during the war, but the police station had miraculously been spared. Thanks to its restrained proportions, sturdy design and traditional materials, it stood out as a model of old-world grace and charm amid the brutalities of the surrounding architecture.

The size of the building belied the modest number of personnel deployed there, having been constructed at a time when the port was much more active than it was now, after interminable labour disputes had diverted much trade south to Salerno. The ground and first floors were the only ones in official use, and the second used only as a dumping ground for forgotten files and broken furniture. As for the top storey, it appeared equally abandoned at this time of day, although once night had fallen it turned into one of the liveliest venues in the whole area, much frequented by sailors who for one reason or another did not have a pass permitting them to leave the port enclave. But Zen was careful to know nothing of this, nor about how the prostitutes who worked there got past the guards at the gate, and still less about the contraband goods and illegal substances which reputedly changed hands on the same premises.