'He knew.' Full of his own anger, Davos had recognised mine. He kept his answer short and left me to deduce for myself the unpleasant follow-on.

'I suppose he used it to taunt the people involved in his normal friendly manner?'

'Yes. He stuck the knife in both of them at every opportunity.'

I didn't need to elaborate, but tried it to put pressure on Davos: 'He ragged Chremes about the marriage he regrets -

'Chremes knows it was the best thing he ever did.'

'And tormented Phrygia over the bad marriage, her lost chance at Epidaurus, and, probably, over her lost child?'

'Over all those things,' Davos answered, perhaps more guardedly.

'He sounds vicious. No wonder you wanted Chremes to get rid of him.'

As soon as I said it I realised that this could be taken as a suggestion that Chremes had drowned the playwright. Davos picked up the implication, but merely smiled grimly. I had a feeling that if Chremes was ever accused, Davos would cheerfully stand by and see him convicted – whether or not the charge was a just one.

Helena, ever quick to smooth over sensitivities, broke in. 'Davos, if Heliodorus was always wounding people so painfully, surely the company manager had a good excuse -and a personal motive – to dismiss him when you asked for it?'

'Chremes is incapable of decisions, even when it's easy. This,' Davos told Helena heavily, 'was difficult.'

Before we could ask him why, he had left the tent.

Chapter XXI

I was beginning to see the picture: Chremes, Phrygia, and where Davos himself fitted in as the old friend who had mourned for their mistakes and his own lost opportunities. When Helena caught my eye, I checked with her: 'What do you think?'

'He's not involved,' she answered slowly. 'I think he may have meant more to Phrygia in the past than he does now, but it was probably a long time ago. After knowing her and Chremes for twenty years, now he's just a critical but loyal friend.'

Helena had been warming some honey for me. She rose and fetched it from the fire. I took the beaker, settling down more comfortably and giving Musa a reassuring smile. For a while none of us spoke. We sat in a close group, considering events.

I was aware of a change in the atmosphere. As soon as Davos left the tent, Musa had relaxed. His manner became more open. Instead of huddling under his blanket he ran his hands through his hair, which had started to dry and curl up at the ends ridiculously. It made him look young. His dark eyes had a thoughtful expression; the mere fact that I could judge his expression marked a change in him.

I realised what was up. I had seen Helena looking after him as if he belonged to us, while he accepted her anxious attentions with little trace of his old wariness. The truth was clear. We had been together for a couple of weeks. The worst had happened: the damned Nabataean hanger-on had joined the family.

'Falco,' he said. I could not remember him addressing me by name before. I gave him a nod. It was not unfriendly. He had not yet attained the position of loathing I reserved for my natural relatives.

'Tell us what happened,' Helena murmured. The conversation was taking place in low voices, as if we were afraid there might be lurking figures outside the tent. That seemed unlikely; it was still a filthy night.

'It was a ridiculous expedition, ill-conceived and ill-planned.' It sounded as if Musa had viewed his jolly night on the town as some military manoeuvre. 'People had not taken enough torches, and those we had were waning in the damp.'

'Who asked you to go on this drinking spree?' I broke in.

Musa recollected. 'Tranio, I think.'

'I guessed it might have been!' Tranio was not my chief suspect – or at least not yet, because I had no evidence – but he was first choice as a general stirrer-up of trouble.

'Why did you agree to go?' Helena queried.

He flashed her an astonishing grin; it split his face apart. 'I thought you and Falco were going to be quarrelling about the play.' It was Musa's first joke: one aimed at me.

'We never quarrel!' I growled.

'Then I beg your pardon!' He said it with the polite insincerity of a man who shared our tent and knew the truth.

'Tell us about the accident!' Helena urged him, smiling.

The priest smiled too, more wickedly than we were used to, but immediately grew intense as he told his story. 'Walking was difficult. We were stumbling, our heads low. People were grumbling, but nobody wanted to suggest turning back. When we were on the cistern's raised embankment, I felt somebody push me, like this – ' He suddenly aimed a hard blow with the flat of his palm against the lower middle of my back. I braced my calves to avoid falling into the fire; he had quite a shove. 'I fell down over the wall -'

'Jupiter! And of course you can't swim!'

Unable to swim myself, I viewed his predicament with horror. However, Musa's dark eyes looked amused. 'Why do you say that?'

'It seemed a reasonable deduction, given that you live in a desert citadel -'

He raised a disapproving eyebrow, as if I had said something stupid. 'We have water cisterns in Petra. Small boys always play in them. I can swim.'

'Ah!' It had saved his life. But somebody else must have made the same mistake as me.

'It was very dark, however,' Musa went on in his light, conversational way. 'I was startled. The cold water made me gasp and lose my breath. I could not see any place to climb out. I was afraid.' His admission was frank and straightforward, like everything he said or did. 'I could tell that the water below me was deep. It felt many times deeper than a man. As soon as I could breathe, I shouted out very loudly.'

Helena frowned angrily. 'It's terrifying! Did anyone help you?'

'Davos quickly found a way down to the water's edge. He was roaring instructions, to me and to the other people. He was, I think:' Musa searched for the word in Greek. 'Competent. Then everyone came – the clowns, the stagehands, Congrio. Hands pulled me out. I do not know whose hands.' That meant nothing. As soon as it became obvious he hadn't sunk and would be rescued, whoever tipped Musa into the water would help him out again to cover his own tracks.

'It's the hand that shoved you in that matters.' I was thinking about our suspects list and trying to envisage who had been doing what on that embankment in the dark. 'You haven't mentioned Chremes or Philocrates. Were they with you?'

'No.'

'It sounds as if we can eliminate Davos as perpetrator, but we'll keep an open mind on all the rest. Do you know who had been walking closest to you beforehand?'

'I am not sure. I thought it was the Twins. A while before I had been talking to the bill-poster, Congrio. But he had fallen behind. Because of the height of the walkway and the wind, everyone had slowed up and strung out more. You could see figures, though not tell who they were.'

'Were you in single file?'

'No. I was alone, others were in groups. The walkway was wide enough; it only seemed dangerous because it was high, and in darkness, and made slippery by the rain.' When he did talk, Musa was extremely precise, an intelligent man talking in a language not his own. A man full of caution too. Not many people who have narrowly escaped death remain so calm.

There was a small silence. As usual it was Helena who faced up to asking the trickiest question: 'Musa was pushed into the reservoir deliberately. So why', she enquired gently, 'has he become a target?'

Musa's reply to that was a precise one too: 'People think I saw the man who murdered the previous playwright.' I felt a slight jar. His phrasing made it sound as if merely being a playwright was dangerous.

I considered the suggestion slowly. 'We have never told anybody that. I always call you an interpreter.'