A mile away, beyond the Golfe-Juan marina, the siren of a police car seesawed through the night. The driver of the second Mercedes stepped from the car and opened the passenger door, beckoning to me. I stared at the dead man on the sand, at his overweight, deflating body. The floating sleeves of his dinner jacket semaphored as the waves swilled up the beach, signalling a death to the sea. I held Frances 's shoes to my face, smelling the perfumed insoles and the fresh scent of brine.

The chauffeur waited while I climbed the sea wall to the Mercedes. He wore evening dress under his bowling jacket, and as I stepped up to him I saw his face and overlit eyes.

'Halder? What are you doing here?'

'Time to leave, Mr Sinclair.'

'You were driving the car? I thought you were guarding Zander…' I pointed to the dead man on the sand, his exposed torso washed by the waves. Halder's face was expressionless. In the headlights of the approaching police car he resembled an accident bystander already bored by the tableau around him, the overturned Audi, a body and the waves. Too distracted to face me, he had distanced himself from any judgement on events.

'We're leaving, Mr Sinclair.' He gestured towards the open passenger door. 'It's best if you come with us.'

A strong hand reached from the rear seat and gripped my wrist.

Too tired to resist, I watched myself step into the car.

'Paul…' Alain Delage drew me towards the jump seat. 'I'm glad we waited for you. I told Jane you'd join us.'

His composed face glowed in the police headlights. As I sat down he smiled with the ready sympathy of a rescuer reaching from a liferaft to help a survivor from the sea.

Facing me, squeezed together in the rear seat, were Jane and Simone Delage, the camcorder across their laps. Jane still wore her black silk dressing gown, and lay half-asleep against Simone's shoulder. Recognizing me, she raised a hand in welcome, and managed a faint flicker of her bloodless lips. I realized that I was still holding Frances Baring's shoes, and placed them on the floor at Delage's feet.

Half a mile behind us, the spotlight of the police car lit up the shacks along the beach. When Halder started the engine of the Mercedes I drummed on the glass behind his head.

'Alain – the police are on their way. We need to talk to them.'

'Not now, Paul.' Delage signalled to Halder. 'The ambulance men will tell them everything. It's been a long day for you…'

He sat back, larger and more confident than I remembered him. The overturned Audi had moved into the deeper water, and the paramedics returned to the beach. They knelt beside the dead security chief, taking a blood sample from his thigh.

Zander's dinner jacket had at last detached itself from his arm. It floated off, working its way across the waves, sleeves moving in a wavering breaststroke, determined to reach the safety of the open sea.

We sped on into an even deeper night.

34 Course Notes and a Tango

'Mr sinclair, you've been most helpful.' Sergeant Jucaud paused at the door and tucked his notebook into his jacket. 'Pascal Zander was a close friend of the Cannes police.'

'As he often said – I'm glad to tell you all I know…'

I shook the young detective's hand and watched him walk back to his car. He paused by the Jaguar, admiring its lines, and knelt by the rear wing. Something out of the ordinary had caught his trained eye, perhaps an unpaid parking ticket snagged by the boot handle. With a small knife he teased a paint fleck from the chromium bumper, then raised it to the sunlight and waved reassuringly to me. The array of dents and scratches marking the Jaguar's venerable bodywork were too slight to suggest that the car had been involved in a serious collision. The miscreant paint fleck had probably come from Wilder Penrose's fibreglass door, still bearing its open wound like a duelling scar. Besides, as Sergeant Jucaud knew, I could hardly have reversed the Audi into the sea.

Careful to remain calm, and glad of the day's first injection, I returned the sergeant's salute. I waited until he had driven away, and then strolled back to the pool. I stared at my reflection in the water, trying to accept that I had spoken for twenty minutes to the sergeant and told him absolutely nothing about the true cause of Zander's death.

A publicity plane was carrying out its morning tour of Eden-Olympia, advertising a clay-pigeon range in the hills beyond Grasse. I lay on the sun-lounger, feeling the guilt and pain ebb from my knee. A faint steam rose from the wet footprints Jane had left on the tiles. Looking at the tiny insteps, I thought of Frances Baring's shoes, with their scent of toes and midnight sea, now wrapped in a supermarket bag in the Jaguar's boot.

In the five days since Zander's death, Frances had not once returned to her office. Her secretary told me that she had taken a fortnight's leave, but her telephone at Marina Baie des Anges had been disconnected. I could still hear her cry of fear when she recognized Zander's body, and her panic as she ran blindly to her car. I needed to see her again, and somehow reassure her that Zander's death had been an accident. Already I had largely convinced myself.

A lethal evening had turned into an even stranger night. I remembered the drive back to Eden-Olympia, when I had been too stunned to demand that Halder stop the car and report the incident to the police. I stared into the night, at the closed filling stations and supermarkets, while Alain Delage flexed his thighs and the two women huddled together in the back of the Mercedes, a secure enclave in a world of violent men. Simone had watched Jane protectively, like a mother with a tired child, warning me away when I tried to take her hands.

As we reached Eden-Olympia I expected a detachment of French gendarmerie to be waiting for us. Too tired to join the others for a nightcap, I climbed the stairs to my bedroom and fell asleep with the light on. I woke an hour later, and heard the sprinklers playing on the cycad below my window. Dance music came from the lounge, the sweet strains and swoops of a 1940s tango. I went downstairs, still wearing David Greenwood's kelp-stained dinner jacket, and found that Jane had revived. She was dancing with Halder, one arm outstretched as he bowed her backwards across his thigh.

The Delages sat side by side in the armchairs, watching the dance like impresarios trying out a scene from a new musical, a tale of tragic love across the divide set in a shabby Buenos Aires dance hall. Halder moved with his light-footed grace, but he looked ill at ease, well aware that the dance might continue once the music had stopped. Alain Delage was filming the tango, and behind the camcorder his face bore the same expression that I had seen during the beating of the African trinket salesman.

I realized that a target was being primed. I stepped through the cigarette smoke and slipped my arm around Jane, who moved through a deep dream of her own and scarcely seemed to notice that her partner had changed. Responding to my clumsy steps, she smiled at me as if recognizing an old acquaintance who had strayed briefly into her life. But Halder bowed to me from the door, all too aware of the danger he had faced.

Alain Delage had taken over as Eden-Olympia's security chief, and Wilder Penrose's prize pupil was now his most eager collaborator.

The introverted and mousy accountant so despised by Frances Baring had turned into a confident and well-adjusted sociopath.

I lay on the sun-lounger, listening to Jane's shower, and glad to have shared a late breakfast with her. Sergeant Jucaud had called at seven, delaying the start of her professional day and providing a small window of opportunity to revive a fading marriage. Sitting with us in the kitchen, the sergeant questioned me about Zander's 'state of mind', a euphemism for drunkenness.