Cato and Macro followed his direction and saw the remains of the dam. A line of rocks stretched across the narrow bottom of the vale and water still trickled from between them. More rocks and shattered timbers lay strewn about the ground in front of the foundations of the dam. The three men picked their way forward and stopped a short distance below the main breach.
‘I’m trying to recall how it looked before,’ said Narcissus. ‘I should have paid more attention to that bore, Apollodorus. Weren’t there some big sticks supporting the middle?’
‘Sticks?’ Cato smiled. ‘I think he called them buttresses.’
Narcissus looked at him and frowned briefly. ‘Buttresses then. I remember he said that they would need plenty of men to shift them when the time came to drain the water behind the dam.’
‘That’s right.’ Cato nodded.
‘So what happened? Where did all these men suddenly come from? There wasn’t anyone near the dam.’
‘Yes … Yes there was,’ Cato replied. ‘You remember that party by a wagon close to the base of the dam.’
Macro nodded. ‘Yes. Can’t have been more than ten of them though. They wouldn’t have been able to shift those timbers. Not by themselves.’
‘No. You’re right,’ Cato conceded.
They picked their way across the muddy debris. Then Narcissus pointed down the vale. ‘Isn’t that one of them? One of those buttresses? Or at least what’s left of it.’
Cato and Macro turned to look. A hundred paces away, to the side of the vale, what looked like a shattered tree trunk stood up at an angle, wedged between two huge boulders. Cato could see that it was too straight and regular to be the remains of a tree. ‘Worth a look,’ he said.
‘Why?’ asked Macro, not liking the look of the mud-encrusted tangles of vegetation that lay between them and the shattered buttress.
‘For the dam to collapse, both of the main supports would have to give way first, right?’
‘So?’
‘So, aren’t you curious about how they did give way?’
Macro gave him a surly look. ‘I could be more curious.’
Cato ignored him and began to clamber across the ruined landscape towards the two boulders. After a moment the other two followed. Cato was examining the thick length of timber when they caught up with him. Some of the buttress was buried in the mud and another six feet or so protruded into the air before ending in a confusion of shattered splinters. Cato was tracing his fingers across what was left of a regular line at the edge of the splinters.
‘Do you see here?’ He moved aside to give them a clear view. Macro stood on tiptoe and squinted.
‘Looks like it’s been sawn.’ He reached up and traced his fingers along the mark. ‘Quite some way into the timber.’
Cato nodded. ‘I’d wager that we’d find the same on the other buttress if we could find it, as well as some of the lesser supports. Weaken enough of them and you’d no longer need hundreds of men to put enough pressure on the timbers to cause them to give way, or shatter under the strain, like this one.’ He patted the timber. ‘Just shift some of the supports and the pressure of the water behind the dam will do the rest.’
Narcissus nodded. ‘As I said, this was no accident, and here is the proof.’
‘There is something else,’ Cato said. ‘When we saw the wave, did you notice how everyone was rooted to the spot?’
‘Yes. What of it?’
‘One man wasn’t. Centurion Tigellinus made a run at Claudius before anyone else gathered their wits enough to react. And he had taken off his heaviest pieces of kit to make sure he wasn’t weighed down.’
Narcissus’s brow furrowed slightly as he recalled the event. ‘Yes, he was quick off the mark. I might have assumed he was going to protect the Emperor, were it not for the fact that he had replaced Lurco.’ He looked at Cato. ‘Are you saying Tigellinus knew about the dam? That that was why they got rid of Lurco, because this was what they had been planning?’
‘Perhaps.’ Cato looked unsure. ‘But how could they know that the Emperor was planning to visit the drainage works? The decision to replace Lurco was made before Claudius decided to come here today.’
‘It’s a big project and has taken years to complete,’ Macro observed. ‘There’s every chance that he would come to see the final stages for himself.’
‘More than a chance,’ Narcissus interrupted. ‘Apollodorus didn’t put on that celebration by himself. It was Pallas’s idea. He organised the celebration and commissioned that cake.’
‘So Pallas is behind this?’ Macro frowned. ‘Pallas is working for the Liberators?’
‘I don’t know,’ Narcissus admitted. ‘It’s possible. But I doubt it. Pallas has nothing to gain from a return to the Republic. In fact he has as much to lose as I have. I doubt that he was behind this attempt on Claudius’s life.’
‘Why not?’ asked Cato. ‘If Claudius drowns then Nero is the most likely successor.’
‘That’s true,’ Narcissus conceded ‘But there were enough people in the palace who knew that the Emperor would be here. Any one of them could be working for the Liberators. However it happened, the Liberators got wind of his visit to the project and decided to bring forward their plan for Tigellinus to assassinate the Emperor. They sabotaged the supports for the dam and Tigellinus knew what was going to happen and made ready to strike in the moment of confusion as the wave came towards us.’
‘It’s a bit far fetched,’ Macro protested. ‘Tigellinus would be putting his life at risk. For that matter, so would those men who were involved in weakening the dam. One wrong step there and the whole thing would have come down on them.’
‘Just shows how determined our enemy has become,’ Narcissus said grimly.
‘They want an assassin close to the Emperor. Whatever plans they have for Tigellinus, the chances are that there would be precious little hope of him escaping having committed the deed. In fact, this business with the dam probably gave him the best possibility to strike and get away with it that he was likely to get.’
Cato nodded. ‘I think you’re right. The trouble is, if this was just an opportunistic attempt, then the initial plan is still ready to go ahead, as long as Tigellinus has survived, or they have another man ready to step into his boots if he hasn’t. We still have to be on our guard. Are you going to tell the Emperor?’
Narcissus hesitated. ‘Not yet. I want to have this investigated. I have to be certain of the facts before I go to Claudius.’
‘Fair enough. There is one thing though. Apollodorus had no hand in this. The wave came as much of a surprise to him as the rest of us. You should put his mind at rest before you have him look at the evidence.’
Narcissus considered the suggestion. ‘Perhaps later on, after he’s been questioned. For now I’m content for people to think that it was an unfortunate accident. That’s clearly what the Liberators want us to think, and I don’t want them running scared just yet. They’re making their move. They failed this time. They will try again if they think we aren’t wise to their conspiracy. The more risks they take, the better the chances we have of identifying and eliminating them.’
‘And the better chance they have of eliminating the Emperor,’ Macro retorted.
‘Then we shall all have to be more alert to potential dangers, shan’t we?’ Narcissus said sharply. He paused and forced himself to continue in a more measured tone. ‘This is my chance to deal with the Liberators once and for all. I should have crushed them many years ago when I had the chance,’ he added bitterly. He continued swiftly, ‘If we force them to go to ground now, then they will bide their time and wait for another opportunity to strike. In the meantime the Emperor will be under constant threat and my agents and I will be stretched to the limit to respond to every possible sign of danger. Better to finish it now, don’t you think?’
Macro looked at him and shrugged. ‘It’s your decision. It’s not really my job to ferret out conspirators. It’s up to you to protect the Emperor.’