Funerals celebrate another frontier crossing, in many ways the most formal and protracted of all. As the mourners waited in the Protestant cemetery, dressed in their darkest clothes, it struck me that they resembled a party of well-to-do emigrants, standing patiently at a hostile customs post and aware that however long they waited only one of them would be admitted that day.

In front of me were Blanche and Marion Keswick, two jaunty Englishwomen who ran the Restaurant du Cap, an elegant brasserie by the harbour. Their black silk suits shone in the fierce sun, a sheen of melting tar, but both were cool and self-composed, as if still keeping a proprietary eye on their Spanish cashiers. Despite the large tip I had left the previous evening, they had scarcely smiled when I complimented them on their cuisine.

Yet for some reason they now seemed more friendly. When I stepped past them, hoping to photograph the ceremony, Marion held my arm with a gloved hand.

'Mr Prentice? You're not leaving so soon? Nothing has happened.'

'I think everything has happened,' I rejoined. 'Don't worry, I'll stay to the end.'

'You look so anxious.' Blanche straightened my tie. 'I know the grave yawns, but there's no room for you there, even though she's the merest slip of a thing. In fact, they could almost use a child's casket. I wish your brother were here, Mr Prentice. He was very fond of Bibi.'

'I'm glad to hear it. Still, it's a fine send-off.' I gestured at the fifty or so mourners waiting by the open grave. 'So many people have turned up.'

'Of course,' Blanche affirmed. 'Bibi Jansen was immensely popular, and not only with the younger set. In some ways it's a pity she ever went to live with the Hollingers. I know they meant well but…'

'It was a terrible tragedy,' I told her. 'David Hennessy drove me to the house a few days ago.'

'So I heard.' Marion glanced at my dusty shoes. 'David's setting himself up as some sort of tour guide, I fear. He can't resist putting a finger in every pie. I think he has a taste for the macabre.'

'It was a tragedy.' Blanche's eyes were sealed within the dark wells of her sunglasses, a lightless world. 'But let's say the sort that brings people together. Estrella de Mar is far closer after all this.'

Other mourners were arriving, a remarkable turn-out for a junior domestic. The bodies of Hollinger, his wife and their niece Anne, together with the secretary, Roger Sansom, had been flown to England, and I assumed that those attending the burial of the Swedish maid were paying their respects to all five victims of the fire.

Immediately beyond the high wall was the Catholic cemetery, a cheerful township of gilded statues and family vaults like holiday villas. I had walked around the graves for fifteen minutes, preparing myself for the bleak Protestant service. Flowers decked even the simplest headstones, and each bore a vitrified photograph of the deceased – smiling wives, cheerful teenage girls, elderly burghers and sturdy soldiers in uniform. By contrast the Cementerio Protestante was a boneyard of coarse soil bleached white by the sun, locked away from the world (as if a Protestant death were somehow illicit), entered by a small gate whose key could be rented at the lodge for a hundred pesetas. Forty graves, few with a headstone, lay under the rear wall, mostly those of British retirees whose relatives could not afford to repatriate them.

If the cemetery was a gloomy place, there were few signs of gloom among the mourners. Only Gunnar Andersson, a young Swede who tuned speedboat engines at the marina, seemed grief-stricken. He stood alone by the waiting grave, thin and stooped in his borrowed suit and tie, a wisp of beard on his gaunt cheeks. He squatted down and touched the damp soil, clearly reluctant to consign the girl's remains to its stony embrace.

The remaining mourners waited comfortably in the sun, talking to each other like members of a recreational society. Together they formed a cross-section of the expatriate business community – hoteliers and restaurateurs, a taxi company proprietor, two satellite-dish agents, a cancer specialist from the Princess Margaret Clinic, property developers, bar-owners and investment counsellors. Looking at their sleek and suntanned faces, it struck me as curious that there was no one present of Bibi Jansen's age, for all the talk of her popularity.

Nodding my respects to the Keswick sisters, I left the main party of mourners and walked towards the graves below the rear wall. Here, as if deliberately holding herself apart from the others, stood a tall, strong-shouldered woman in her late fifties, platinum hair tightly crowned by a wide-brimmed black straw hat. No one seemed willing to approach her, and I sensed that a formal invitation was needed merely to bow. Behind her, serving as her baby-faced bodyguard, was the bar steward from the Club Nautico, Sonny Gardner, his yacht-rigger's shoulders constrained by a smart grey jacket.

I knew this was Elizabeth Shand, Estrella de Mar's most successful businesswoman. A former partner of Hollinger's, she now controlled a web of companies in the property and service sectors. Her eyes surveyed the mourners with the ever-watchful but tolerant gaze of a governor at a light-regime prison for executive criminals. As if keeping up a private commentary on her charges, her lips murmured to themselves in an almost louche way, and I saw her as part martinet, part bawdy-house keeper, the most intriguing of all combinations.

I knew that she was a major shareholder in the Club Nautico and a close colleague of Frank's, and was about to introduce myself when her eyes moved sharply from the grieving Swede and fixed themselves on a late arrival at the cemetery. Her mouth opened with a rictus of such distaste that I expected the mauve lipstick to peel from the irritated skin.

'Sanger? Good God, the man's got a nerve…'

Sonny Gardner stepped forward, buttoning his jacket. 'Do you want me to see him off, Mrs Shand?'

'No, let him know what we think of him. The sheer neck of it…'

A slim, silver-haired man in a tailored tropical suit was making his way over the rough ground, his slender hands parting the air. He moved with light but deliberate steps, his eyes searching the diagram of stones around him. His handsome face was smooth and feminine, and he had the easy manner of a stage hypnotist, but he was clearly conscious of the hostile mourners stirring around him. His faint smile seemed almost wistful, and he now and then lowered his head, like a sensitive man aware that because of some minor quirk of character he had never been liked.

Clasping his hands behind his back, he positioned himself at the graveside, the soil breaking under his patent-leather shoes. I assumed that he was the Swedish pastor of some obscure Lutheran sect to which Bibi Jansen had belonged, and that he was about to officiate at her interment.

'Is this the pastor?' I asked Gardner, whose flexing arms threatened to split the seams of his jacket. 'He's rather curiously dressed. Is he going to bury her?'

'Some say he already has.' Gardner cleared his throat, looking for somewhere to spit. 'Dr Irwin Sanger, Bibi's "psychiatrist", the one mad person in the whole of Estrella de Mar.'

I listened to the cicadas rasping while the mourners stared with varying degrees of hostility at the silver-haired newcomer, and reminded myself that there were far more tensions below the surface of this charming beach resort than first seemed apparent. Elizabeth Shand was still staring at the psychiatrist, clearly disputing his right to be present. Protected by her baleful presence, I raised my camera and began to photograph the mourners.

No one spoke as the sounds of the motor-drive echoed off the walls. I knew they disapproved of the camera, as they did of my continued presence at Estrella de Mar. Watching the mourners through the viewfinder, it occurred to me that almost all of them would have attended the Hollingers' party on the evening of the fire. Most were members of the Club Nautico and knew Frank well. None, I had been relieved to find, accepted that he was guilty.