After a quarter of an hour on Sinatra, by which time his silken coat was dark brown with sweat, Ricky changed her on to Kinta, the widow-maker, who required the brute strength of a Juan O’Brien to halt her wilful stampede.

‘This should be even more fun,’ hissed Frances to Louisa.

‘She rides jolly well,’ conceded Louisa.

‘Ricky’ll never put up with this kind of lip.’

Perdita’s method of stopping Kinta was simple. She rode her flat out at the brick wall at the end, which must have been five foot high. Sitting still in the saddle, she made no attempt to pull her up. Unable to stop, Kinta had no option but to hoist herself over the wall, just catching it with a cannon bone and pecking on landing.

‘I think we’ll walk back, you stupid bitch,’ Perdita chided the hobbling pony as she opened the gate and returned to the ring.

‘What the fuck d’you think you’re playing at?’ White with rage, Ricky bent down to examine Kinta’s leg.

‘Teaching her a lesson. Look how she’s learnt it.’ Swinging Kinta round, she hurtled her towards the wall.

‘Stop,’ yelled Ricky too late.

As if she were doing a dressage test, Kinta swivelled round, changing legs perfectly, hurtled down to the far corner and turned again.

‘Blimey cubed,’ said Louisa in amazement.

‘You keep forgetting to stop in a straight line,’ said Ricky, determined not to praise her, ‘and you never look round to check who’s behind you. Anyone coming down the line would take you clean out.’

‘Nobody here,’ shrugged Perdita.

‘It’s got to be instinctive for when there is someone,’ said Ricky. ‘Look, look and keep looking into the distance, never at your hands.’

At that moment a yellow-and-crimson hot-air balloon came over the hill, letting out a great recharging snort. Kinta, nervy at the best of times, jerked up her head, hitting Perdita smartly on the nose.

Totally unsympathetic, Ricky ordered her to go on circling the ring, doing small turns. For Perdita, frantically wiping away blood as it splattered her and Kinta, the session deteriorated sharply. Ten minutes more on Kinta were followed by twenty minutes on Wayne, Ricky’s favourite pony, still circling, turning, then swinging round and putting her left hand on Wayne’s custard-yellow right quarter at the trot, until her face and neck were streaming with sweat and blood, and her mascara and eyeliner were smeared and making her eyes sting.

Wayne flattened his big donkey ears and rolled his bruised dark eyes in martyrdom. Like an instinctive footballer who doesn’t need to train, he was appalled to be subjected to such boring manoeuvres. The sun grew hotter.

‘I will not give in, I will not give in,’ said Perdita through clenched teeth. Her tits were agony, bouncing around. But just as she was about to crack, Ricky signalled to Frances to bring in a bucket of polo balls. Wayne perked up as Ricky smoothed out the pitted sand in the centre with his boot and put down a ball.

‘We’ll start off with the nearside forehand, so you want him on the nearside leg.’

Desperate to show what she could do, Perdita completely mis-hit three balls in a row.

‘You’re not watching the ball.’

Wayne, getting crafty, skedaddled so near the ball that she couldn’t hit it without bashing his legs. She missed again.

‘Fucking hell,’ she screamed.

‘Now she’ll go to pieces,’ said Frances happily.

‘Come here,’ said Ricky.

Dripping with sweat and blood, make-up streaking her face like a clown caught in a deluge, Perdita rode sulkily up to him.

‘Calm down,’ he said gently. ‘You’re going too fast and getting uptight, and he knows it. And keep at him with your left leg or he’ll move in.’

Back she went, chattering with rage and panic. ‘Please God, or he’ll never take me on.’

Slowly Ricky took her through it. ‘Don’t cut the corner; up out of the saddle; bend over; look at the ball; begin your swing; keep watching the ball; head over the ball.’

Crack! Stick and ball connected in an exquisitely timed shot.

‘Bingo!’ Perdita threw her stick into the air, ten feet high, and caught it. ‘That was perfect.’

‘You hit it too late, and don’t throw your stick in the air. It’s dangerous.’

‘Better a stick in the air than a stick-in-the-mud!’

The galloping fox weather-vane was motionless in the swooning heat. Beneath it the stable clock said two fifteen. She had been riding for two hours, nearly twice the length of a normal match.

‘We’ll try one more thing,’ said Ricky.

Louisa led out two ponies – Willis, a huge bay, invaluable because he had the best brakes in Rutshire, and Hermia, a little chestnut mare Ricky had bought in Argentina in 1981, who was very green and terrified of everything.

Ricky mounted Willis. Perdita clambered wearily on to Hermia. Her ribs and shoulders were agony, her back ached, her thighs were raw where the sweating jodhpurs had rubbed them. Her hands could hardly hold Hermia’s reins as she followed Ricky a hundred yards down a wooded lane, past an empty, leaf-strewn swimming-pool. Here, in two and a half acres of lush, green grass, framed by midge-filled trees, lay Ricky’s stick-and-ball field.

Next year’s tiny catkins were already forming on the hazels. Ricky noticed the reddening haws and remembered how little Millicent used to shut her eyes to avoid the prickles as she delicately picked the berries off the thorn trees. Overwhelmed with bitterness at the hand fate had dealt him, he saw no reason why he should show others any mercy.

‘Now, do everything I tell you,’ he yelled to Perdita as he kicked Willis into a gallop. The big bay’s stride was longer than Hermia’s and Perdita had to really motor to keep up. Halfway up the field, Ricky shouted, ‘Turn!’

‘He’s crazy,’ raged Frances in anguish. ‘If he has a fall, his arm’s buggered for good.’

Four times Ricky raced up and down the field, executing sharper and sharper turns. Now he was hurtling towards two orange-and-white traffic bollards which served as goal posts up the other end.

‘Ride me off,’ he bellowed.

Perdita spurred Hermia on, but she was just too far behind. Ricky’s knee and the shoulder of his horse hit Hermia so hard that she seemed to fly four feet through the air. Perdita was still reeling when Ricky turned and was riding back. ‘Ride me off again.’

The fourth time Perdita was knocked clean out of the saddle and only stayed mounted by clinging to the mare’s neck.

‘Bastard,’ she screamed as she righted herself.

But by now Ricky had reached the opposite end of the field. ‘Now ride towards me. Towards me! Towards me! Don’t duck out! Keep going!’

The mighty Willis was thundering at them like a Volvo on the motorway. Perdita could feel Hermia quailing and about to bolt. It was all she could do to keep her on course.

She could see Willis’s red nostrils as big as traffic lights, his white-edged eyes, the flashing silver of his bit. They must crash, they must.

‘Stop,’ yelled Ricky, swinging Willis to the left. Obedient to their masters, Willis and Hermia skidded to a halt, so close that Hermia’s head brushed Willis’s quarters, and Perdita was deposited on the grass, all the breath knocked out of her aching body.

‘You bloody fool,’ she croaked.

‘I told you not to sit so far forward. Get up, you’re not hurt.’

‘I know I’m bloody not, but you might have been. You risked a head-on collision and wrecking your arm for ever, just for the sake of putting me down. You’re crazy.’

Just for a second Ricky smiled.

‘At least you’ve given me back my nerve. Go and have a shower and we’ll have lunch.’

‘Doesn’t look so sexy now, does she?’ said Frances spitefully, as a dusty, blood-stained Perdita hobbled into the yard, wincing as she led Hermia.

‘Oh, I don’t know,’ said Joel.

‘She’s jolly brave,’ said Louisa. Kind-hearted and admiring, she followed Perdita into Hermia’s box.

‘You OK?’

‘Fine.’ Perdita leant against the wall, fighting back the tears.

‘I’ll see to Hermia,’ said Louisa, ‘and show you where the shower is.’

After she’d found Perdita a towel and some soap, she handed her a pair of pants and a long, white T-shirt with bananas and oranges embroidered on the front.

‘I thought you might want to change.’

‘Thanks,’ said Perdita slowly. ‘Sorry I was bloody beforehand. I was absolutely shit-scared.’

‘Needn’t have been,’ said Louisa. ‘Joel and I thought you did brilliant. The hot water’s erratic, but there’s plenty of cold.’

Twenty minutes later Perdita joined Ricky in the kitchen. He was drinking Coke, eating a slice of ham between two pieces of white sliced bread and reading The Times sports page. He rose six inches from his chair as she came in. At least he recognizes I’m female, thought Perdita, encouraged.

Louisa’s T-shirt, several sizes too big for her, fell to a couple of inches above her knees. Her hair, wet from the shower, was slicked back, the alabaster skin was without a scrap of make-up. Her nose was swollen, her big curved mouth looked as though bees had stung it, and her wary, dark eyes were still bloodshot from the dust.

‘That’s better. You look like a human,’ said Ricky. ‘If you ever turn up tarted up like that again, you go straight back to your play-pen. What d’you want to drink?’

‘Vodka and tonic,’ said Perdita, chancing her arm.

‘Not if you’re going to play polo. Most top players hardly drink or smoke,’ he added, removing her packet of cigarettes and throwing it in the bin.

‘There were four in there,’ said Perdita, outraged. ‘Anyway, the twins smoke.’