So I filled them all in and we sat back, aghast and disturbed by the implications in Paula's story. We were running into something which got steadily nastier. Campbell approved of my wanting her evidence written down, preferably legally attested, though I wasn't sure if she would commit herself so far.

Clare said, changing the subject, 'Mike, I've been giving the diary some thought and especially the drawings, and I think I've come up with something. Can we all go up to Pop's suite after breakfast?'

Geordie assented reluctantly. He was anxious to get back to his ship, but we persuaded him that all would be well for a couple of hours more. They're good lads, plenty to do and they know where you are if they want you,' I said firmly. So after breakfast we found ourselves seated round a coffee table in the suite, already sweating gently in spite of the air conditioning, and with the sunshine of Panama calling to us through the open windows. Clare laid out the diary and tracings in front of us.

'I've been working backwards, from where we know Mark was, to see if we can identify any more of the drawings. The very last one is what looks like a monocle, and I think I know what it is – but only because we do know where Mark was. I think it means Tahiti.'

'How the hell can it mean Tahiti?' said Campbell.

'They're also known as the Society Islands. And a monocle is the epitome of the uppercrust, the "society" bloke. It's lean, but could it do?' She looked anxiously for my opinion.

I laughed. 'As well as anything. Crude but effective. Go on.'

'Numbers 31 and 30 I can't see at all – perhaps Geordie might, if he knows the area well. One's a cow and one's a -well, it's this.' She pointed to an object like an irregular, flattened semicircle standing on a flat base. It was connected to the cow with the word 'OR', and made no sense at all to any of us.

'Then we come to these. The Fair Goddess and The Disappearing Trick, a woman and an eagle.'

I interrupted her. They are the two that come immediately before his high cobalt assay figures. I think they may be crucial.'

'Good,' she said briskly. 'Because there are lots more possibilities. I've been thinking about the woman. I think she could be La France – you know, Uncle Sam for America, John Bull for Britain and this female – Marianne – for France. You see her in newspaper cartoons.'

Campbell looked at the drawing intently. 'You may have something there. This thing on her head is the Cap of Liberty, isn't it? What's the extent of French territory in the Pacific?'

'French Oceania – about a million square miles of it, including Tahiti, Bora-Bora, the Tuamotus, the Marquesas, the Austral Islands. You'd have to get it down much closer than that.'

The Marianas Islands,' said Geordie and he sounded very glum. 'The Marianas Trench.'

Clare looked thrilled. 'Where are they?'

'A long way off, too far for comfort. Almost alongside the Philippines,' I said. 'It just can't be there, or else why was Mark so far away from it? I don't believe it.'

But Geordie had thought of something else. 'Suarez-Navarro's ship is heading that way.'

We looked at one another in dismay. 'Just doesn't feel right,' I said, only because I didn't want it to be. 'We want something down this way.'

Campbell said, 'What's this about a goddess? Marianne isn't one.'

'Let's go through a list of goddesses,' I suggested. There's Venus for a start. Is there a Venus Island?'

Geordie grinned. 'I've heard of the Good Ship Venus, but not an island. Wait a minute, though – there's a Venus Point in Tahiti.'

That sounds promising,' said Campbell.

'It's too close ashore – and all round there has been dredged.'

'Not so promising,' said Campbell glumly, 'but we'll keep it in mind.'

'Let's carry on with the goddess list,' said Clare. 'What about Aphrodite?'

We all thought about that. 'Nothing doing,' said Geordie finally.

'It could be a French name,' said Campbell.

I was brutal about it. 'Or a Polynesian name. Or a Polynesian goddess.'

'Good grief,' said Campbell, 'we're getting nowhere fast.'

We ran through the pantheon and couldn't even make a start on the Polynesian tribal deities without a single degree in anthropology amongst us. We switched our combined brains to the problem of the eagle, got nowhere, and came back to La France. Clare gazed fiercely at the drawings. 'All right, one last try. Let's go through it all once more.'

We all groaned.

'Venus.'

'Tahiti,' muttered Campbell, whose attention was waning.

'Demeter.'

Still nothing doing.

'Athena.'

Campbell said, 'I think this whole whacky idea is wrong. Let's pack it up.'

Clare gave a shout of laughter. 'I've got it – she's not La France at all, she's Athena, the goddess of justice. Mark used "fair" in the sense of "fair play".'

'Not that he knew much about that,' Geordie said.

'What about the Cap of Liberty?' I asked.

'It's not – it's a Roman helmet. She ought to have a spear too.'

'But Athena wasn't a Roman,' objected Campbell. 'She was a Greek goddess.'

I said, 'The Roman equivalent was Minerva – what about that?'

Geordie thumped the table and burst out laughing. 'My God! I think that's it – I should have seen it before. Recife de Minerve, of course!'

Campbell said, 'You mean there is such a place?'

I was struggling with a memory. I'd read about the place and there was something very out of whack about it, but I couldn't recall what it was. Geordie couldn't stop laughing. 'There's been a shipwreck on it. Oh, this is too damn funny.'

Campbell rubbed his hands, his interest rekindled. 'Now we're getting somewhere – where is it? Obviously down this way?'

'Down south of the Tuamotus,' said Geordie.

'Is it worth a trip?' Campbell asked me. 'You're the expert here.'

I thought that it was only a remote possibility that we'd hit on the right spot on our very first guess, and that there'd probably be a lot of false alarms on the way, unless some much more concrete evidence came up; but on the other hand I didn't want the expedition to founder through lack of either activity or enthusiasm – and we had to start somewhere. 'It could have possibilities,' I said, voicing a little of my reservation. 'It partly depends on where it is, which is what Geordie's going to tell us.'

'Are you kidding?' said Geordie, still spluttering over his private joke. 'Nobody – not even the Royal Navy – knows where Minerva is.'

There was a dead silence. Campbell broke it. 'What the hell do you mean by that?'

'I mean this,' said Geordie, suddenly sober. 'The Navy looked for it but couldn't find it. I suppose it's all in the Pacific Islands Pilot – I'd have to look – but there's an account of it in a book I've got on board.'

'But what is it?' Clare asked.

'Just what it says. Recife de Minerve. Minerva Reef. It's a hidden shoal.'

Geordie left us to go down to Esmerelda. Apart from fetching the book he was anxious to know if all was well, and to supervise the beginning of the restocking for sea. He also had to arrange for a cabin for Clare, which I knew would mean a little crowding up for someone else. We agreed that we might as well get on with things, and that all being well we should be able to sail within a day or so; impatience was in the air. I decided to try and have another word with Paula, who had left a note for me, containing her address. I had another idea that I wanted to try out on her.

I used the phone in the foyer and got her at once. 'Paula, it's Mike. I'd like to talk to you again.'

'Sure,' she said sleepily, and I guessed that late nights singing meant late mornings lying in. 'When – now?'

'If I can.'

'Okay. I'll see you in that little bar up the street.'

She was waiting for me, sitting at the same table, 'Hi,' she said. 'What's on your mind?'