‘She’ll need a fleet of sofas to accommodate the coverage of Tristan’s arrest,’ said Wolfie.

‘Probably been kept away from her, if she’s so ill. I do hope she’ll see us. Tristan also said she was terribly mean. The estate’s next to a golf course, and she rushes out, grabs any lost balls and wraps them up for her nieces and nephews for Christmas. Tristan realized she was losing it last birthday when she sent him a blackboard with the letters of the alphabet round the frame.’

Wolfie stopped Lucy’s rattling by asking her irritably if she remembered everything Tristan had ever told her.

‘Probably.’ Lucy flushed an even more unbecoming shade of red.

Wolfie noticed the anguished way she glanced at every farm-building they passed as if she was expecting some horrific content of battery hen or veal calf.

‘Oh, no,’ she wailed, as he slowed down behind a lorry, ‘they’ve got lambs in there. I bet they haven’t been watered for yonks.’

Nearly removing the side of the hired car, as he shortened her misery by overtaking the lorry, Wolfie snapped that she’d got to toughen up.

‘You can’t suffer for every squashed earwig in this world.’

‘Hortense suffered,’ protested Lucy. ‘She claimed that the best years of her life were spent fighting for the Resistance, despite being captured and tortured by the bloody Krauts— Oh, Wolfie, I’m sorry.’

‘I’m used to it,’ said Wolfie calmly. Then, catching sight of two fat men towing trolleys and sweating in plus-fours, ‘Here’s the golf course, and there’s the château.’

To repel intruders, two hissing stone Montigny snakes were chained to the pillars on either side of the big iron gates. Ahead at the end of an avenue of limes and flanked by ancient arthritic oaks stood a grey, square house with its pale grey shutters closed against prying eyes and the afternoon sun.

The good news was that all Hortense’s greedy relations had temporarily pushed off to another family house in Brittany to celebrate the sixty-fifth birthday of Tristan’s eldest brother Alexandre, the judge. With them, leaving the coast even clearer, had gone the even greedier Dupont, who was already carrion-crowing at the prospect of a large cut of Hortense’s estate.

The bad news was that Hortense, who’d kept such iron control of her life, was now lying upstairs under a mosquito net, morphinised up to the eyeballs, recognizing no-one.

‘Yesterday, she was convinced the Bolsheviks had taken over the château,’ sighed Florence, the kind, plump housekeeper, who was almost as old as her mistress. ‘Today the Nazis have moved in, and she’s back in the Resistance. So I’m afraid you won’t be very welcome,’ she added apologetically to Wolfie.

‘But Tristan could be in prison for life,’ begged Lucy. ‘The police think he killed Rannaldini to stop him spreading some vicious tale about his parentage.’ If she hadn’t seen a flicker of fear in Florence’s faded grey eyes, Lucy might not have persisted. ‘Hortense is the only person who might know the truth,’ she went on. ‘Please let me stay in case she regains consciousness.’

Florence was wavering when there was an imperious skidding crunch in the gravel and Rupert, resplendent in a pale yellow suit and grey striped shirt, emerged from a cloud of dust and a hired Mercedes. Apparently unaffected by the heat, he made Lucy feel plainer and hotter than ever.

‘What are you doing here?’ she snapped.

‘Resisting arrest, disobeying the orders of Gablecross, casing the joint. Bonjour, Madame.’ Slipping into effortless French, Rupert turned all his charm on Florence.

Absolutely bloody typical, fumed Lucy. She’ll take one look and roll over. But fortunately it seemed that Aunt Hortense loathed men, particularly those who looked like blond Luftwaffe pilots, almost as much as Germans. Rupert was sent packing as summarily as Wolfie.

Lucy, who was allowed to stay on for a little while, couldn’t hide a suspicion that both men were glad of an excuse to escape.

‘We’ll go back to La Reconnaissance and chivvy ambassadors,’ said Rupert, sauntering towards the Mercedes. ‘Join us for dinner if you can get away.’

‘We’ll leave everything in “your loyal hands”,’ quoted the ever-pragmatic Wolfie, clearly delighted at a chance to ingratiate himself with Tabitha’s father.

Frantic with thirst, Lucy gulped down a whole jug of orange pressé. Heat was coming in great waves through the kitchen window. Only endless sprinklers kept the garden green. Beyond, like purple shagpile, stretched fields of lavender.

Once the maid had disappeared to shop in Montvert, Florence relented and got out the family scrapbooks she’d kept since Tristan was a little boy. It wrung Lucy’s heart to see him always hovering at the edge of family groups, like an outfielder desperate not to miss a smile that miraculously Étienne might one day throw him.

At least the later scrapbooks were crowded with Tristan’s cuttings. Florence had already pasted in the marvellous reviews of The Lily in the Valley, dominated by the luminous beauty of Claudine Lauzerte.

To stop herself falling asleep, Lucy begged to be given a tour of the house. Downstairs big high rooms papered in cranberry reds, Prussian blues and deep snuff browns were the ideal setting for the Impressionist collection, acquired ahead of fashion in the late nineteenth century, and for Étienne’s great powerful oils, but not to lighten the heart of a little boy. Everywhere frayed tapestries of hunting scenes hung above cabinets lovingly painted with fruit, flowers and birds. Leggy gold tables and chairs seemed poised to race through the french windows into a park shimmering with heat-haze. You couldn’t see the mountains for dust.

The great hall housed the family portraits.

‘That was Louis who died at Crécy, and Edouard who was wounded at Agincourt, and there’s Blaize,’ Florence ran her finger inside the frame to test for dust, ‘who died in Spain on a secret mission. He was murdered by the Spanish Inquisition.’

Lucy peered at Blaize in excitement. Handsome, hawk-faced, with dark cynical watchful eyes, he was definitely a Montigny, and one of the reasons Tristan had embarked on Don Carlos.

‘And there’s Henri, painted by David,’ said Florence proudly, ‘Such a great general that Napoleon coaxed him out of exile to fight at Austerlitz and Borodino. The Montignys have always been a great military family.’

Soldier-citizens of the world like Posa, thought Lucy.

‘Tristan’s brother Laurent was brave, wasn’t he?’

‘More hotheaded,’ said Florence, somewhat disapprovingly. ‘A pied-noir builder fell off a ladder here one day. Madame Hortense rang six doctors but none would treat him. Laurent jumped in the Jeep, drove to the nearest, put a shotgun to his temple, and didn’t remove it until he’d come back and set the leg.’

‘How romantic,’ sighed Lucy. ‘No wonder Tristan hero-worships his memory. Why isn’t there a painting of him?’

Florence glanced round nervously.

Laurent’s portrait had hung in the hall, she admitted, smiling a welcome to everyone coming through the front door. But Étienne was so devastated when he was killed, the painting was locked away with everything else in his room.

‘But surely after Étienne’s death…’ protested Lucy.

‘He left instructions in his will that the door was to remain locked.’

‘At least let me look at Tristan’s room.’

‘It was very small.’ Florence looked unhappy. ‘When Tristan went to university Étienne turned it into an en suite bathroom.’

Don’t show your anger, Lucy had to keep telling herself.

‘There should be a portrait of Tristan. He’s the handsomest of the lot,’ she said crossly.

In answer Florence looked up at the gilt Montigny snake chained to the lintel. ‘“Seek not to disturb the serpent,”’ she whispered, her face creasing into a hundred folds of anxiety.

‘I’m only seeking to disturb the wretched thing’, Lucy was nearly in tears, ‘because I want to find out the truth. Tristan was desperate to question Hortense about his parents, but he was too busy with Carlos to fly out, and now it may be too late.’

‘It was a secret, Madame swore to Étienne she would take to the grave.’ Florence glanced up at a gold Empire clock, which featured Neptune brandishing his trident. ‘The nurse will be going in ten minutes. You can sit with her instead of me.’

Aunt Hortense had blurred, weather-beaten features and wild white hair, like a gargoyle caught in a snowstorm. She lay without covers, her long nightgown rucked up to show purple bruised shins and a plaster on every toe. Beside her on the bed were two marmalade cats and a tiny brindled Italian greyhound, which one of her gnarled, ringed, gardening-begrimed hands repeatedly caressed.

Opposite the bed, filling the wall, was a ravishing Rubens of milkmaids tending a herd of paddling red cows and chatting up a swain driving a horse and cart.

‘We hung it there last week,’ whispered Florence. ‘Madame wanted something beautiful to look at.’

To the right hung a small photograph of a young Hortense being handed the Croix de Guerre for her courage during the Resistance. With her boyish brown curls, her deep-set dark eyes and quick smile, she bore an uncanny resemblance to Tristan.

Perhaps? wondered Lucy. But Hortense would have been too old at fifty-five. Could she have had an illegitimate daughter? She must have a story to tell.

In moments of consciousness, Aunt Hortense played la grande dame for all her worth. ‘I wouldn’t dream of discussing family matters with a complete stranger,’ she told Lucy coldly.