'Hennessy…?' Tired of this charade, I left the bathroom and moved through the shadows towards the bed. 'Switch on a light, old chap. We'll be able to see ourselves playing the fool.'

The intruder collided with a suitcase, stumbled and fell across the bed. A skirt flared and a woman's thighs flashed in the moonlight. A coil of thick black hair scattered itself over the pillow, and a scent of sweat and panic filled the room. I bent down and held the woman's shoulders, trying to lift her on to her feet, but a hard fist punched me below the breastbone. Winded, I slumped on to the bed as she thrust herself away from me. I reached out and seized her hips, pulled her on to the pillows and pinned her hands to the headboard, but she wrenched herself from me and knocked the bedside lamp to the floor.

'Leave me alone!' She struck my hands away, and I saw a strong chin and fierce teeth in the sweeping beam of the lighthouse. 'I told you – I won't play that game any more!'

I released her and sat on the bed, rubbing the bruised pit of my stomach. Setting the lamp on the bedside table, I straightened the shade and switched on the bulb.

'Dr Hamilton?'

Kneeling in front of me, her hair in a dishevelled mane around her torn blouse, was the young physician who had arrived at the funeral with Hennessy and Bobby Crawford. She seemed startled to see me, eyes in a slight divergent squint as she tried to take in all four walls of the room and my presence on the bed. She quickly recovered, setting her lips firmly across her teeth, glaring up at me like a cornered puma.

'Doctor, I'm sorry…' I reached out to help her. 'I think I hurt you.'

'Leave me alone. Just keep away from me and stop that heavy breathing. You'll hyperventilate.'

She raised her hands to fend me off, then stood up and smoothed her skirt around her thighs. She winced over her bruised knees, and in a show of temper kicked the suitcase that had tripped her. 'Bloody thing…'

'Dr Hamilton… I thought you were -'

'David Hennessy? Good God, how much time do you spend rolling about on a bed with him?' She rubbed her flushed wrists, spitting on the skin. 'For a clumsy man, you're certainly strong. Frank must have had his work cut out with you bumping around him.'

'Paula, I didn't realize who you were. All the lights were off.'

'It's all right-when you grabbed me I was expecting someone else.' She managed a quick smile and began to examine my face and chest, sweeping her hair over her shoulders so that she could see me. 'It looks as if you'll live-I apologize for the uppercut. I'd forgotten how strong a frightened woman can be.'

'Just don't take up kick-boxing – I'm sure there are classes here.' Her scent clung to my hands, and without thinking I wiped them on the pillow. 'Your perfume – I thought it was David's aftershave.'

'Are you staying here? You'll smell me all night. What a dreadful thought…' She buttoned her blouse, watching me with some curiosity and perhaps matching me against Frank. She stepped back and bumped into the other suitcase. 'Good God, how many of these things are there? You must be a menace at airports. How on earth did you become a travel writer?'

Her handbag lay on the floor, contents scattered around the bedside table. She knelt and replaced her car keys, passport and prescription pad. Between my feet lay a postcard addressed to the staff at the Club Nautico. As I handed it to her I saw that it carried a reproduction of a tourist photographer's snapshot of Frank and Paula Hamilton outside Florian's bar in the Piazza San Marco. Muffled in heavy coats against a misty Venetian winter, they were grinning like honeymooners. I had seen the postcard in Frank's desk, but scarcely glanced at it.

'Is this yours?' I handed the postcard to her. 'You look as if you had fun.'

'We did.' She stared at the photograph and tried to straighten a creased corner. 'That was two years ago. Happier days for Frank. I dropped by to look for it. We sent it together, so it's partly mine.'

'Keep it – Frank won't mind. I didn't know you were…'

'We're not. Don't excite yourself thinking about it. We're good friends now.'

She helped me to straighten the bed, plumping the pillows and tucking in the sheets with crisp hospital corners. It was easy to imagine her lying in the darkness before I arrived, postcard in hand, thinking of her holiday with Frank. As Bobby Crawford had said, behind the professional poise she presented to the world she seemed distracted and vulnerable, like an intelligent teenaged girl unable to decide who she really was, perhaps suspecting that the role of efficient and capable doctor was something of a pose.

When she slipped the postcard into her bag she smiled sweetly to herself, and then checked this little display of affection, pursing her lips over her strong teeth. I sensed that she wanted to give in to her feelings for Frank, but was held back by a fear of exposing her emotions, even to herself. The testy humour, and the edgy manner of someone unsettled by standing more than a few seconds in front of a mirror, would have appealed to Frank, as it did to me. I guessed that Paula Hamilton had always moved through life at an oblique angle, detached from her emotions and sexuality.

'Thanks for the help,' I told her when we had rearranged the furniture. 'I wouldn't want to shock the maid. Tell me, how did you get in here?'

'I have a key.' She opened her handbag and showed a set of door keys to me. 'I meant to give them back to Frank but never quite got around to it. Too final, I suppose. So you're moving into the apartment?'

'For a week or so.' We left the bedroom and stepped on to the balcony, breathing the cool night air with its hints of jasmine and honeysuckle. 'I'm trying to play the older brother, without any success. I need to be closer to things if I'm going to get Frank out of this nightmare. I tried to talk to him this morning at the court in Marbella, but no luck. To be honest, he refused to see me.'

'I know. David Hennessy spoke to Frank's lawyer.' She touched my shoulder in a sudden show of sympathy. 'Frank needs time to think. Something terrible happened to the Hollinger. It's upsetting for you, but try to see things from his point of view.'

'I do. But what is Frank's point of view? That's one window I can't open. I take it you don't think he's guilty?'

She leaned against the rail, hands drumming the cold steel in time to the distant disco beat. I wondered what had brought her to the apartment – the postcard seemed a trivial pretext for a midnight visit – and why she had previously refused to see me. She kept turning to look at my face, as if unsure whether she could confide in someone who resembled Frank, but was nonetheless a larger and clumsier version of her former lover.

'Guilty? No, I don't… though I'm not all that sure what guilty means.'

'Paula-we know exactly what it means. Did Frank set fire to the Hollingers' house? Yes or no?'

'No.' The reply was less than prompt, but I suspected that she was deliberately drawing me on. 'Poor Frank. You saw him on the day you arrived. How was he? Is he sleeping properly?'

'I didn't ask. I assume there's not much else to do except sleep.'

'Did he tell you anything? About the fire, and how it started?'

'How could he? He can't have any more idea than you and I.'

'I don't suppose he has.' She strolled along the balcony, past the giant ferns and succulent plants, to the far end where three chairs were drawn up around a low table. A white sailboard leaned against the wall, its mast and rigging beside it. She pressed her hands against the smooth hull, as if laying them against a man's chest. The lighthouse beam moved across her face, and I saw that she was biting her injured lip, reminding herself of whatever accident had bruised her mouth.