He said, 'I'd like to see the bunch of thugs who'd stand up against some of your dad's old mob. They may be getting older, but they're not that old and they're all trained commandoes. They're not all settled down and married, you know.'

'What do you think you're doing – setting up a private army?'

'Might not be a bad idea,' he said. 'If the other night is a sample of what to expect we might need a bloody army.'

I sighed. 'All right, Sergeant Wilkins. But no one who's married or has other responsibilities, and you'd better hold your hand until we get Campbell tied up. We can't do anything without money.'

'Ah yes, the money,' said Geordie, and looked very sad.* 3*

The following morning, quite early, I had a visit from the Inspector and one of his men. Geordie was already out and I was impatient to begin my search for Kane, but tried not to show it. The Inspector was cagey and suspicious, but very casual. I think his trouble was that he didn't really know what to be suspicious of.

He asked, 'Know anyone in South America?'

'Not off hand. No, I don't,' I said.

'Um. The man you killed may have been a South American. His clothes were labelled from Lima, Rio and Montevideo. He could be from almost anywhere except Brazil.'

'I think that answers one question. I couldn't place the accent. What was his name?'

The Inspector shook his head. 'That we don't know, Mr Trevelyan. Or anything else about him, yet. Are you quite sure you don't know any South Americans?'

'Positive.'

He changed tack. 'Wonderful thing, this science; I've found out everything there is to know about manganese nodules.'

I said dryly, 'then you know more than I do – they're not really my line. Did you find it interesting?'

He smiled sourly. 'Not very – they're about as valuable as road gravel. Are you sure there wasn't anything else in that suitcase that might have been of value?'

'Inspector, it was just junk. The kind of stuff that anyone might carry in a case, apart from the nodules, that is.'

'Looks as though Mr Wilkins might have been right, after all. You surprised the burglars before they could pinch anything else.'

I didn't fall for that one – the Inspector didn't for one moment believe it was an ordinary break-in. I said non-committally, 'I think you're right.'

'The inquest will be next Wednesday,' he said. 'You'll get an official notification, both of you.'

'I'll be there.'

Then they were gone and I thought about South America. That was nearer the Pacific than Spain, but apart from that it made no particular sense to me. And then, belatedly, I thought of Mark's connection with Jonathan Campbell, and Campbell's reputed connection with some South American mining venture, and I had something else to chew on. But it still made no sense, and for the time being I gave up.

Finding a rich Canadian in London's millions was a damn sight easier than finding a poor Australian. The rich are circumscribed in their travelling. The Institute gave me the address of the conference centre, and they gave me the address of the hotel Campbell was staying at, and I had him at the third phone call. Campbell was blunt and curt to the point of rudeness. Yes, he could give me half an hour of his time at eleven that morning – it was already nine-thirty. His tone indicated that if he thought I was wasting his time I'd be kicked out in the first two minutes. The telephone conversation lasted only that long.

At eleven I was at the Dorchester and was shown up to Campbell's suite. He opened the door himself. Trevelyan?'

'Yes, sir.'

'Come in.'

He led the way into a room once a luxury living-room but now fitted out as a temporary office, complete with desk, files and secretary; he sent her out and seated himself behind the desk, gesturing me to sit opposite. He was a broad, stocky man of about sixty with a square, tanned face lined with experience. Somebody once said that after forty a man is responsible for his own face; if that's so then Campbell had had a lot of responsibility in his time. His eyes were a frosty blue and his hair iron grey and grizzled. His clothes were expensive and only the slightest accent indicated his transatlantic origin.

I decided that attack was the best policy. I produced the half-nodule and put it on his blotting pad. 'That assays at ten per cent cobalt,' I said without preamble.

He picked it up and looked at it carefully, masking any curiosity. 'Where did it come from?'

'The bottom of the Pacific.'

He looked up and stared at me, then said, 'Are you any relation of the Mark Trevelyan who worked for me a while back?'

'He was my brother.'

'Was?'

'He's dead.'

Campbell frowned. 'When and where did he die?'

'About four months ago – in the Pacific.'

'Sorry to hear it,' he said but perfunctorily. 'A good scientist.'

I detected the careful note in his voice, and thought that here was someone else who had seen through Mark, or had had some example of how my brother went about his affairs. I wondered if it was a business problem, or if it had had anything to do with his daughter's relationship with Mark. I couldn't assess whether it was going to make things harder or easier for me.

He carried on looking at me rather than at the specimen. Trevelyan – I've heard the name more recently. Oh yes!' He turned and produced a tabloid newspaper from a shelf and shook it out. 'Are you the Trevelyan mentioned here? The one who killed a man defending his home? An Englishman's castle and all that stuff?'

I caught a glimpse of the headline: SCIENTIST KILLS BURGLAR. Quite mild, considering the paper. I nodded. 'That's right.'

He pursed his lips and put aside the paper, and then came back to business. This is a manganese nodule. There are billions of them lying on the bottom of the Pacific. There are quite a few in the Atlantic too.'

'Not many there,' I said. 'And the quality's poor. Too much sedimentation.'

True.' He tossed the stone and caught it. The highest cobalt assay so far is a fraction over 2 per cent. That one came from the central Pacific. Where did this one come from?'

I looked at him blankly and shook my head. He smiled suddenly and it transformed his face – he had a very charming smile. 'All right, I tried,' he said. 'You'd be surprised how often it works. Do you know why I am able to reel off facts about manganese nodules?'

'I was wondering.'

'Your brother told me,' he said. 'He wanted me to fit an expedition a couple of years back. I must say I was tempted.'

'Why didn't you?'

He hesitated, then said, 'I lost a packet in South America. It caught me off balance and until I reorganized I didn't have any fluid capital. About that time your brother left my company, and he hadn't left me enough to go on by myself.'

'I hope you're better placed now,' I said dryly. 'Because that's why I've come to you – now it's my turn to ask you to fund an expedition.'

'So I gathered,' he said, equally dryly. He touched the nodule. 'I must say you brought more than your brother did. He talked a good story but he never showed any concrete evidence. You say this assayed at ten per cent cobalt?'

'I assayed it myself yesterday afternoon – the other half, that is.'

'Mind if I have this assayed – independently?'

'Not at all,' I said equably.

He laughed, showing his charm again. 'All right, Trevelyan, I won't need to. I'm convinced of this anyway.'

'I'd prefer it if you did,' I said. 'I could do with corroboration. But I must tell you that what you've got in your hand is all the evidence I have to show.'

His hand clenched around the nodule. 'Now you do begin to interest me. I think you have a story, Mr Trevelyan. Why don't you tell it and quit beating around the bush?'

I had already decided that if we were to work together at all I must hold nothing back. It was only moderately risky. So I told him everything, and when I'd finished we were well past my original half hour. He listened in absolute silence until I was done and then said, 'Now let's see if I've got all this straight. One, your brother died out in the Pacific; two, a man called Nelson whom you have never heard of sent you a case which contained notebooks and nodule samples; three, Kane shows up and pitches what you think is a cock-and-bull yarn; four, the suitcase is stolen by presumed South Americans with additional violence including one killing; five, you retain one nodule, analyse it and find a fantastic percentage of cobalt; and six, you also retain a diary of your brother's which you can't even read.'