Pompeii

air near to the ground itself. If the air had come out in greater quantity it would have harmed people too; but the abundance of pure air extinguished it before it rose high enough to be breathed by people.

    Again, the language seemed too flowery to be the work of Exomnius, the execution of the script too professional. In any case, why would Exomnius have claimed to have just heard about an earthquake which had happened seventeen years earlier? And who was Lucilius? Corelia had leaned across to read the document over his shoulder. He could smell her perfume, feel her breath on his cheek, her breast pressed against his arm. He said, 'And you are sure these were with the other papryi? They could not have come from somewhere else?'
    'They were in the same box. What do they mean?'
    'And you didn't see the man who brought the box to your father?'
    Corelia shook her head. 'I could only hear him. They talked about you. It was what they said that made me decide to find you.' She shifted fractionally closer to him and lowered her voice. 'My father said he didn't want you to come back from this expedition alive.'
    'Is that so?' He made an effort to laugh. 'And what did the other man say?'
    'He said that it would not be a problem.'
    Silence. He felt her hand touch his – her cool fingers on his raw cuts and scratches – and then she rested her head against his chest. She was exhausted. For a moment, for the first time in three years, he allowed himself to relish the sensation of a having a woman's body close to his.
    So this was what it was like to be alive, he thought. He had forgotten.

    After a while she fell asleep. Carefully, so as not to wake her, he disengaged his arm. He left her and walked back over to the aqueduct.
    The repair work had reached a decisive point. The slaves had stopped bringing debris up out of the tunnel and had started lowering bricks down into it. Attilius nodded warily to Brebix and Musa who were standing talking together. Both men fell silent as he approached and glanced beyond him to the place where Corelia was lying, but he ignored their curiosity.
    His mind was in a turmoil. That Exomnius was corrupt was no surprise – he had been resigned to that. And he had assumed his dishonesty explained his disappearance. But these other documents, this piece of Greek and this extract from a letter, these cast the mystery in a different light entirely. Now it seemed that Exomnius had been worried about the soil through which the Augusta passed – the sulphurous, tainted soil – at least three weeks before the aqueduct had been contaminated. Worried enough to look out a set of the original plans and to go researching in Pompeii's library.
    Attilius stared distractedly down into the depths of the matrix. He was remembering his exchange with Corax in the Piscina Mirabilis the previous afternoon: Corax's sneer – 'He knew this water better than any man alive. He would have seen this coming' – and his own, unthinking retort – 'Perhaps he did, and that was why he ran away. ' For the first time he had a presentiment of something terrible. He could not define it. But too much was happening that was out of the ordinary – the failure of the matrix, the trembling of the ground, springs running backwards into the earth, sulphur poisoning... Exomnius had sensed it, too.
    The fire of the torches glowed in the tunnel.
    'Musa?'
    'Yes, aquarius?'
    'Where was Exomnius from? Originally?'
    'Sicily, aquarius.'
    'Yes, yes, I know Sicily. Which part exactly?'
    'I think the east.' Musa frowned. 'Caetana. Why?'
    But the engineer, gazing across the narrow moonlit plain towards the shadowy mass of Vesuvius, did not reply.

JUPITER

    24 August

    The day of the eruption

Hora prima

    [06:20 hours]

'At some point, hot magma interacted with ground-water seeping downwards through the volcano, initiating the first event, the minor phreato-magmatic eruption which showered fine-grained grey tephra over the eastern flanks of the volcano. This probably took place during the night or on the morning of 24 August.'
Volcanoes: A Planetary Perspective

    He kept his increasing anxiety to himself all through the sweltering night, as they worked by torchlight to repair the matrix.
    He helped Corvinus and Polites on the surface mix the wooden troughs of cement, pouring in the quicklime and the powdery puteolanum and a tiny amount of water – no more than a cupful, mind, because that was the first secret of making a good cement: the drier