'We need to know the current situation from the California end,' said Dicky with a sigh. I knew that sigh. Dicky was just getting me prepared for a sweaty week in Mexico City while he went to swan around in southern California.

'Talk to the Biedermanns,' I said. 'It's easier.'

'Stinnes asked about the Biedermanns,' said Werner. 'He asked if I knew them. I used to know Paul very well, but I told Stinnes I knew the family only from the newspapers.'

'Werner, you didn't tell me you know the Biedermanns,' Zena interjected excitedly. 'They are always in the gossip columns. Poppy Biedermann is beautiful. She just got divorced from a millionaire.'

Dicky looked at me and said, 'Better you talk to Biedermann. No sense in me showing my face. Keep it informal. Find out where he is; go and see him. Would you do that, Bernard?' It was an order in the American style: disguised to sound like a polite inquiry.

'I can try.'

Dicky said, 'I don't want to channel this through London, or get Frank Harrington to introduce us, or the whole world will know we're interested.' He poured himself some iced water and sipped a little. He was recovering some of his composure, when suddenly he screamed, 'You bastard!', his eyes fixed on poor Werner and his head thrust forward low over the table. Werner looked perplexed until Dicky, still leaning forward with his head almost on his plate, yelled, 'That bloody cat.'

'Cherubino, you're very naughty,' said Zena mildly as she bent down to disengage the cat's claws from Dicky's leg. But by that time Dicky had delivered a kick that sent Cherubino across the room with a howl of pain.

Zena stood up, flushed and furious. 'You've hurt her,' she said angrily.

'I'm awfully sorry,' said Dicky. 'Just gave way to a reflex action, I'm afraid.'

Zena said nothing. She nodded and left the room in search of the cat.

'Paul Biedermann is approachable,' said Werner, to cover the awkward silence. 'He arranged a bank guarantee for me last year. It cost too much but he came through when I needed him. He has an office in town and a house on the coast at Tcumazan.' Werner looked at the door but there was no sign of Zena.

'There you are, then,' said Dicky. 'Get on to him, Bernard.'

I knew Paul Biedermann too; I'd exchanged hellos with him recently in Berlin and hardly recognized him. He'd smashed himself up driving a brand-new Ferrari back to Mexico from a drunken party in Guatemala City. At 120 miles an hour the car had gone deep into the roadside jungle. It took the rescuers a long time to find him, and a long time to cut him free. The girl with him had been killed, but the inquiry had glossed over it. Whatever the truth of it, now one of his legs was shorter than the other and his face bore the scar tissue of over a hundred neat stitches. These infirmities didn't help me overcome my dislike of Paul Biedermann.

'Just a verbal report. Nothing in writing for the time being. Not you, not me, not Biedermann.' Dicky was keeping all the exits covered. Nothing in writing until Dicky heard the results and arranged the blames and the credits with godlike impartiality.

Werner shot me a glance. 'Sure thing, Dicky,' I said. Dicky Cruyer was such a clown at times, but there was another, very clever Dicky who knew exactly what he wanted and how to get it. Even if it did sometimes mean giving way to one of those nasty little reflex actions.

The jungle stinks. Under the shiny greenery, and the brightly coloured tropical flowers that line the roadsides like the endless window displays of expensive florists, there is a squelchy mess of putrefaction that smells like a sewer. Sometimes the road was darkened by vegetation that met overhead, and strands of creeper fingered the car's roof. I wound the window closed for a moment, even though the air-conditioning didn't work.

Dicky wasn't with me. Dicky had flown to Los Angeles, giving me a contact phone number that was an office in the Federal Building. It was not far from the shops and restaurants of Beverly Hills, where by now he would no doubt be sitting beside a bright blue pool, clasping an iced drink, and studying a long menu with that kind of unstinting dedication that Dicky always gave to his own welfare.

The big blue Chewy he'd left for me was not the right sort of car for these miserable winding jungle tracks. Imported duty-free by Tiptree, Dicky's embassy chum, it didn't have the hard suspension and reinforced chassis of locally bought cars. It bounced me up and down like a yo-yo in the pot-holes, and there were ominous scraping sounds when it hit the bumps. And the road to Tcumazan was all pot-holes and bumps.

I'd started very early that morning, intending to cross the Sierra Madre mountain range and be in a restaurant lingering over a late lunch to miss the hottest part of the day. In fact I spent the hottest part of the day crouched on a dusty road, with an audience of three children and a chicken, while I changed the wheel of a flat tyre and cursed Dicky, Henry Tiptree and his car, London Central and Paul Biedermann, particularly the last for having chosen to live in such a God-forsaken spot as Tcumazan, Michoacan, on Mexico's Pacific coast. It was a place to go only for those equipped with private planes or luxury yachts. Getting there from Mexico City in Tiptree's Chewy was not recommended.

It was early evening when I reached the ocean at a village variously called 'Little San Pedro' or 'Santiago', according to who directed you. It was not on the map under either name; even the road leading there was no more than a broken red line. Santiago consisted only of a rubbish heap, some two dozen huts constructed of mud and old corrugated iron, a prefabricated building surmounted by a large cross and a cantina with a green tin roof. The cantina was held together by enamelled advertisements for beer and soft drinks. They had been nailed, sometimes upside-down or sideways, wherever cracks had appeared in the walls. More adverts were urgently needed.

The village of Santiago is not a tourist resort. There were no discarded film packets, paper tissues or vitamin containers to be seen littering the streets or even on the dump. From the village there was not even a view of the ocean; the waterfront was out of sight beyond a flight of wide stone steps that led nowhere. There were no people in sight; just animals – cats, dogs, a few goats and some fluttering hens.

Alongside the cantina a faded red Ford sedan was parked. Only after I pulled in alongside did I see that the Ford was propped up on bricks and its inside gutted. There were more hens inside it. As I locked up the Chewy, people appeared. They were coming from the rubbish heap: a honeycomb of tiny cells made from boxes, flattened cans and oil-drums. It was a rubbish heap, but not exclusively so. No women or children emerged from the heap; just short, dark-skinned men with those calm, inscrutable faces that are to be seen in Aztec sculpture: an art form obsessed with brutality and death.

The smell of the jungle was still there, but now there was also the stink of human ordure. Dogs – their coats patchy with the symptoms of mange – smelled each other and prowled around the garbage. One outside wall of the cantina was entirely covered with a crudely painted mural. The colours had faded but the outline of a red tractor carving a path through tall grass, with smiling peasants waving their hands, suggested that it was part of the propaganda for some long-forgotten government agricultural plan.

It was still very hot, and my damp shirt clung to me. The sun was sinking, long shadows patterned the dusty street, and electric bulbs, which marked the cantina doorway, made yellow blobs in the blue air. I stepped over a large mongrel dog that was asleep in the doorway and pushed aside the small swing-doors. There was a fat, moustachioed man behind the bar. He sat on a high stool, his head tipped forward on to his chest as if he was sleeping. His feet were propped high on the counter, the soles of his boots pushed against the drawer of the cash register. When I entered the bar he looked up, wiped his face with a dirty handkerchief and nodded without smiling.