We stayed in the area for another week, quartering the submarine valley and dredging at selected spots. The material poured in and I was kept busy. A much more detailed survey would be done later – all I was aiming at was to put limits on the area and to find out roughly how rich, and how consistent it was.

Esmerelda was a happy ship in those days. Not that she hadn't been before, but the depression caused by a fruitless search had lifted and everyone was keen and cheerful. There was a lot of skylarking among the crew, although it always stopped when there was serious work to be done.

Once, when I was having a breather on deck, Paula joined me.

'I don't know what came over me the other day, Mike – you know, when Mr Campbell said I had a share in all this.'

'It is a bit of a shock when you find yourself suddenly on the verge of riches. I went through it too.'

'I never thought of being rich,' she said. 'I never had the time, I guess. I've always been on the move – the States, Mexico, Australia, Tahiti, Hawaii, Panama. Guess I was a bit of a hobo.' She looked up. 'That's what you British call a tramp, isn't it?'

'That's right.'

'I guess I was that too – in the American sense, I mean,' she said sombrely.

'You're all right, Paula,' I said warmly. 'Don't worry about it. Enjoy the idea instead. What will you do with all your new-gotten wealth?'

'Gee, I don't know, Mike. I'm not like Clare – she's used to money, but I'm not. And the way her pop talks sometimes makes my head spin, the way he juggles his millions.'

'Maybe you can go on a cruise ship to sunny Tahiti,' I said jokingly.

But she shook her head violently. 'No. I'll never go there again – I never want to see Papeete again.' She was silent for a while and we stood together companionably, and then she said, 'I think I'll go home first. Yes, I think I'll go home.'

'Where's home?'

'In Oregon. Just a small town – there aren't many big ones in Oregon. It's called Medford. I haven't been there for years – and I should never have left it.'

'Why did you leave, Paula?'

She laughed. 'Oh, it's a bromide – a cliche, you'd say. My whole life's been a cliche. I got movie-crazy when I was a kid, and when I was sixteen I won a local beauty competition. That gave me a swelled head and a big mouth – you should have heard me talk about what I was going to do in Hollywood. I was going to knock 'em cold. So I went to Hollywood and it knocked me cold! There are too many girls like me in Hollywood. I told you the story was a cliche.'

'What happened after Hollywood?'

'The cliche continued. I drifted around, singing in cheap night spots – you know the rest, or you can guess it.' I was saddened by the bitter resignation in her voice. 'That place where you found me in Panama – that was the best paid job I ever had in my whole life.'

'And you left it – just like that? Just because I asked you to?'

'Why not? It – it was Mark, you see. Oh, I know how you feel about Mark, I've heard you talk. All right, supposing he was a lousy no-good? I guess I always knew that, but – I loved him, Mike. And I suppose I was stupidly hoping to find out if he'd ever loved me. I always wanted to do whatever I could for him.'

I remained quiet. There was nothing I could say to that.

'Yes,' she went on quietly. 'I do think I'll go home. I always boasted that I wouldn't go back until I was a success. I guess they'd call me a success now, Mike?' There were tears in her eyes.

'You've always been a success,' I said gently, and held her shoulders.

She sniffed a bit and then said, shaking her head briskly, 'This isn't getting the glassware washed. I'd better go back to work. But thanks.'

I watched her walk along the deck and for the thousandth time I damned Mark's soul to hell. At a touch on my elbow I turned to find Geordie. 'I didn't want to bust up the tete-a-tete,' he said, 'so I waited a bit.' He nodded along the deck. 'Falling for her, Mike?'

'Nothing like that,' I said amusedly, thinking how very off target Geordie's guesses were. 'But there are times when I wish Mark had never been born.'

'Gave her a bad time, did he?'

'Curiously enough, he made her very happy. But he broke her heart by getting himself killed. Not that that matters -he'd have found some way of doing it, sooner or later. What's on your mind, Geordie?'

'I want to talk to you about our next move,' he said. 'We can't stay out here much longer, Mike. The winch and its components really desperately need attention. We're a little low on water – we hadn't had time to top up completely in Nuku'alofa – and that goes for fuel too. And we've been using an awful lot of that for station-keeping. We'll have to put into port somewhere pretty soon.'

'Yes, my lab stocks are running low too. Look, Geordie, we're really finished here – I've got loads of data to work on already. Let's put it to the boss again.'

Campbell said, 'How soon can you finish here, then?'

'I am finished, virtually. This last dredge today could be it-otherwise I could go on tinkering forever.'

That's it then. But we don't go back to Nuku'alofa, in case Ramirez is still there, or hunting for us in that area. We'll go to Fiji-to Suva.'

I hesitated. That's fine, but I'd like to have a look at Falcon.'

'What for?'

I said, 'Well, it's responsible for all this.'

'A scientist to the last, eh? You're not content with finding anything – you want to know when and how and why.'

I was desperately keen to visit the island – or the site of it. I added, to give force to my argument, 'It could well give us a lead to other high-cobalt areas hereabouts. Maybe concentrations of other metals – once we find out something about the mechanism of this thing.'

He laughed. 'Okay, Mike, I guess you've earned it. If Geordie gives the go-ahead we'll go to Suva by way of Falcon.'

Geordie wasn't too certain. He pulled out his charts, measured distances, and grumbled. 'How long are you staying there?'

'Only a day or so, if that.'

'Will you be dredging?'

'There'll be no need to dredge. It's very shallow over the site. A good swimmer like Bill Hunter could go down and collect the samples I want by hand – it won't be more than a few fathoms. And he's dying to show off his talent. We could be away again in just a few hours.'

'It's cutting it a bit fine,' he complained. 'We'll be damned low on water by the time we get to Suva – and it's a good job you don't want to dredge because I really think this one was our last. We have to keep enough fuel oil for manoeuvring and for emergencies – I can't spare any more for the winch motor.'

'Away with you, Geordie. You know you hate sailing under power.'

But I got him to agree in the end. We finished with the dredge and stowed the cable for the last time. The dredge bucket was secured on deck and Geordie set a course northward for Fonua Fo'ou.

That evening in the saloon I said, 'I'd like to summarize what I've found. Can you stand another short lecture?'

We were moving briskly along with a helpful wind, the treasure had been found and any danger seemed infinitely remote and unlikely. My seminar settled down to hear me out in a state of contentment.

Campbell said, 'I'm getting used to being lectured to by scientists; it's sometimes boring and usually profitable.'

I laughed. 'This time it's very profitable.' I produced my charts and notebook. The high-cobalt nodules seem to be concentrated in a valley or depression, twenty miles wide and a hundred miles long. The nodules lie in varying degrees of richness and density.'

Clare, whom I had discovered to my pleasure to be a quick natural mathematician, said in astonishment, 'But that's two thousand square miles.'

'Quite an area,' I agreed. The richness varies roughly with the depth of the water, from about two per cent at the top of the ridges to a peak of ten per cent in the valley bottom – an inverse curve, if you like. On the other hand, the density varies in a different way. At the extreme north of the valley the density is only half a pound per square foot. At the other end it peaks out at fifty pounds per square foot.'