Fortified by two long Bellinis, and one of Venice's delicious quiches, as they had missed breakfast at the hotel, Miranda and Andy decided to pack as much of the treasures of Venice into the rest of the day as possible. They were swallowed into the crowds in St Marks but Andrea was able to see some of the golden mosaics which Miranda loved. Something about the fine intricacy of the craftwork involved in creating such huge pictures appealed to the perfectionist in Miranda, with her love of detail. She quoted Michelangelo at Andrea. "Trifles make perfection, and perfection is no trifle."

But the crowds in St Marks's and in the Doges' Palace finally drove them back outside, and they headed for another very famous church, just round the corner. The Church of San Zaccaria was full of art treasures, and enough gold leaf to satisfy even Miranda.

It also housed one of the most luminous paintings in Venice, the Serene Madonna altarpiece by Bellini. The church was blessedly almost empty, and the light pouring in through the round windows landed right on the faces of the people in the painting.

They were four saints, two men and two women standing round the Virgin with the Christ child on her knee, in a very ornate stone built temple. Maybe the female saints were there, because the church had originally been part of a women's monastery, for aristocratic nuns, said Miranda.

Andy read the information board, and pulled a face. "Oh dear, it says here the saints are St Catherine and St Lucia. They are each holding symbols of their torture and the way they died. St Catherine has the wheel she was broken on, and poor St Lucia is holding a dish with her eyes in it! Presumably she was blinded before she was killed. How horrible."

"Yes it is. But at least they are there, speaking up for themselves. It's unusual. And look at the angel sitting on the steps in the front. He is playing the viol, just like Monteverdi played, and see how the light catches his face. It almost looks as though he could jump out of the painting and join us here. I cannot believe this painting has hung here for five hundred years. How many people must have stood as we are now and gazed on it. It's like a window onto another world. If only we could step through."

Miranda's face had a pearly light of its own as she looked up at the altarpiece. Andrea wondered about her, whether she was still feeling dizzy. She took her arm and drew her gently to one side. She suddenly felt very protective of her mistress-goddess, who looked such a small woman in the centre of all this magnificence and history.

Miranda shook herself back into the present. She had the ability to focus so acutely on something, it made her who she was. She was single-minded when she needed to be, to the exclusion of everything else, and Andy, with her wrap-around multi-tasking abilities, and outside awareness of a million things happening at once was the perfect foil for her, but they certainly looked at the world in a different way.

When they eventually left the church, Miranda was still thinking about the exquisite depiction of the angel's fingers playing the viol, while Andy was still angry about the awful way St Lucy had met her death. She hoped it was just a legend, but she feared not.

However, the day was sunny and warm, all of Venice lay at their disposal, and once she had confirmed that Miranda's dizzy feelings didn't seem to be anything to worry about, Andy took her arm and dragged her over the Accademia Bridge to explore the other side of the canal. They walked as far as the Peggy Guggenheim gallery where they enjoyed tea in the garden, after Miranda sniffed her way round the renowned collection of modern art work in the American heiress's collection.

"Not my cup of tea," she said disparagingly, using the old British expression, as she consumed the very same drink from a fine china cup. "All those careless daubs and drips. You cannot compare it to the art we have seen in other places here."

Andrea chuckled, and saved up the expression to tell Nigel later about Miranda's assessment of all post 1900 art. "Daubs and drips."

"OK, honey, well let's go into the Accademia galleries then, and you can put me right about what's in there, if you feel up to it."

Miranda smiled. She was relieved that Andrea seemed to have recovered from the shock of hearing too much information about Gloria. But she was sensitive enough to know, that when Andy really thought it through, there was likely to be another explosion of rightful fury at not being told the truth about her when they had first been introduced.

She felt very guilty, not about her previous love-life, but about concealing it, but there was nothing she could do now but brace herself for a real period of being in the dog-house. This would be a new and uncomfortable place to sit, as Andrea had barely said a cross word to her since they had first met, as boss and minion.

The girl had never retaliated to her icy taunts and controlled fury, even in the old days. She had simply punished Miranda's many cruel put-downs by returning them with extra sweetness, and thus rendered them pointless, disarming her far more effectively than if she'd fought back with sulks or a temper tantrum. The few tears Miranda had glimpsed her shedding on a rare occasion, had stabbed into her own soul, as she realised all her haughty attempts to push Andy away had simply wounded herself, and made her love the kid even more.

The very idea that Andrea could ever stop loving her, now filled Miranda with terror. She looked across at the engagement ring on her young lover's left hand, matching her own, which she never removed, even to wash or sleep, and clung to a faith that she could add a gold band to it within a month.

Andy misunderstood her silence. "Are you well, darling? Would you prefer to go back to the hotel to rest until this evening?"

"Oh no, not at all. I was just thinking how much I adore you, and how that shade of red really suits your skin-tone. Let's finish our tea and do as you suggest. We have plenty of time to look in the Accademia, and as you might expect, I have a little wish-list of paintings in there I would like to see and show you."

And she put down her tea-cup and stood up to go. The crowded tea-room actually fell silent as she passed regally out. She looked so like an A list celebrity that the largely American crowd of dressed-down tourists all felt they had seen someone famous, though they couldn't quite figure out whom.

Andy smiled at the room encouragingly as she followed her through the door. She knew just how they felt. But Miranda had slipped away oblivious of the effect she was having. In many ways, she was not a vain woman at all, and Andy suspected she never knew just how beautiful she was.

When they eventually returned to the hotel Miranda was feeling light-headed again, and wondered if they should cancel going to hear the recital. She didn't want to embarrass Andy by fainting as she had when she'd realised Charles was probably her brother, at his recital back in California. That had been mortifying. She lay on their bed now for twenty minutes with her feet raised up on a pillow, and thought it through.

No, having bought the tickets and promised Maggie they'd see her again, she decided to take a chance and return to the Frari for the evening. She didn't feel ill exactly, just out of herself. It was a very strange sensation.

She kept thinking of the angel in San Zaccaria, almost as if she could hear the music he was playing. In fact this whole trip to Italy had so heightened her artistic sensitivities that when she looked at colours she could hear music, and when she heard music she could see colours. Maybe her brain was simply becoming overloaded.

Andrea was consulting her phone, and heard from the twins by way of a text message sent from the top of a hill in Ohio, according to Caroline. They were having a ball, camping out with the horses, she said, and Grandpa Richard had taken the horse trailer thirty miles further away from the city into some forest tracks and glades. Granny Jen and Grandpa Richard had one tent, and they had another. It all sounded fine, and with an April heatwave in Ohio, they hadn't felt the cold at all.

"Cassie's still obsessed with the ponies," she read, "But that's OK cos then she doesn't mind doing most of the feeding and grooming. Please keep Mom safe, and see you soon. We'll be returning home to the ranch the same day you fly back into New York." It was all in text shorthand, but Andy could translate.

Andy relayed this news to Miranda. "No mention at all of your divorce, so Mom must have worked her magic. Bless her, she's keeping them away from the news for the whole time until we get back. But a break in the backwoods might just be doing her and Dad a power of good as well. They both work far too many hours and rarely take a vacation."

She texted a long and loving message back, and sent it pinging off into the ether.

Miranda did some stretches while lying down, and then jumped out of bed, prepping herself to sally forth again. They walked the mile or so back to the Frari Church by 7.45, and entered, having met up with Maggie in the doorway. She was still floating about in linen clothes of an indeterminate era, and with her scarf wrapped several times round her neck.

She had found them three good seats at the end of a row near the front, from where they could see all the performers. The singers had been joined by a quartet of viols, the precursor to a string quartet, and Miranda was reminded once again that she was blessed to have a brother who was a virtuoso cello player.

She wondered if Charles could play the viola de gamba as well. She longed to see him, as his scheduled visit to New York in March had had to be postponed due to a fire at one of the venues. They settled down to listen to what promised to be a popular recital, for the great church was more than three-quarters full.

It was after the first set of songs that Miranda began to sense that something was going on very, very strangely inside her head. The music seemed to be penetrating more and more into her brain, sweetly, but almost drowning out her own breathing. And the lights, the great sweep of the pillars, the whole interior of the church began to wave up and down, undulating in time with the ground bass of the music.

The tingling feeling she had had before in her head was now spreading throughout her body. She felt she was losing her balance, and reached out her left hand in fear to grasp Andrea's hand next to her. For a few seconds she couldn't feel it, and began to panic, as though she was floating off the floor.

Immediately, Andy said quietly but intensely, "Don't worry. I've got you! Then, she could hear Andy begin to panic a little as well. "Oh my God what's happening? It's affecting me as well." She grabbed Miranda's fingers and tugged her close.

With their hands entwined, they clung to each other as the only sure thing, for the whole of their surroundings including the oblivious Maggie McIntyre, began to shimmer and shake. It could have been an earthquake, but Miranda could see that no-one else around them in the Church was affected.

She began to feel herself transforming into something other than a sensible New Yorker in 2005. Her identity became something other than she recognised. She was a woman listening to music, but apart from that?

As the polyphonic singing wound its way round the pillars, the very air around her, the very smell of the church seemed to change, to be transformed. The chair under her disappeared, but she was definitely sitting on something. She looked down and there seemed to be some sort of rough bench beneath her now, and the lights, the lights changed to candles. Her hair seemed very long, her clothes likewise, she seemed almost smothered in layers of wool and silk. Who was she? Where was she? Damn, when was this? Miranda would have cried out, but her power of speech seemed to have disappeared.

Andy meanwhile, also tried to speak again, to cry out even, but her voice was swallowed up in the churning atmosphere, the music and the unfamiliar scary sense of displacement. All she remembered were Caroline's words in the text message, "Please keep Mom safe", so she clung to that thought and held tightly onto Miranda's hand, even as she felt her being pulled away from her. Something was tugging Miranda into another time, another dimension. She could feel the magnetic pull, but absolutely refused to give up clinging to her.

Even with the terror of it, there was something liberating in this sense of disembodiment. Miranda felt she was almost flying now, even while staying in her place. The other members of the audience were just shadows, only the music, and the incessant feeling of air waves moving around her seemed real.

And Andy as well of course, Andy's hand in hers, strong, warm, steady. Andy was grounding her. Andy would keep her safe. She felt like a kite with Andy holding the string. The music from the early seventeenth century was luring her to some place apart, some lovely place. But she knew she had to stay in her own time, to return to her own children, to marry Andrea, to be who she was.

The "weird thing," (which was how she and Andy would both call it ever after,) lasted for Miranda maybe fifteen minutes, and while it was happening to her she was trapped, motionless to the outside world's view, but floating between planes of consciousness in a way she could not explain in any logical way.

Then the set of madrigals finished and a halftime break was called. The world mercifully suddenly stopped undulating and spinning. Her chair was once again her chair. The lighting was once again reassuringly electric, and the humans around her regained their bodily forms. The scents in the air stopped being musty and smelling of cloves. She looked down at her own sharply cut clothes, and felt her short bob.

Andrea regained her ability to speak. She hung onto Miranda for dear life and whispered fiercely. "It wasn't just you! I felt it too, maybe not as strongly, but it was definitely there. We were being pulled into something very strange, perhaps another reality, maybe another time even."

Miranda just stared intently at her. She couldn't work out what to say or how to react. It was all too intense. But sensible Andy knew what she needed, to find some fresh air, to get outside, and find some food before going back to the hotel.

She made their apologies to Maggie, who by now could see that Miranda looked very pale and close to fainting. Maggie wanted to call the emergency water ambulance and take them back that way, but Andy managed to dissuade her.

"No, we'll just find something to eat and return slowly to our hotel. You return inside and enjoy the second half of the concert. Miranda's just a little tired. It's been a long day, and we haven't eaten. You know jet lag is a funny thing, it may even be that. The music was lovely, but I think we've had enough."

No way was she going to discuss with a stranger what had happened to them. Out through the great main door and across the piazza, she led Miranda by the hand, finally exchanging a nonchalant wave with Maggie as if nothing much had happened, and then walking firmly forwards through the little winding streets with Miranda tucked on her arm.

Only when she could feel her beloved's heartbeat steadying and the colour returning to her face did she pause, and led them both to a table outside a taverna. A waiter was on to them immediately and she summoned up enough Italian to order two expressos, and two long cold glasses of still water.

"No," croaked Miranda, "San Pellegrino please, I think I need the bubbles." He disappeared inside, and Miranda gave a long shiver. "You did feel it? It wasn't just me?"

"No, I definitely felt it. Maybe not as intensely as you, but it was definitely something. Our whole world wobbled for almost fifteen minutes. It was something to do with the music. I think it lifted you, and then me, up into itself somehow. It was as though time wrinkled back. Something was pulling you, but I wasn't going to lose you, not when I'd just told Caroline I'd keep you safe."

"I could have gone. If it wasn't for you holding on, I might have gone."

"But you didn't. You're safe with me."

"How can we explain it? Was it my fault?"

"No, of course not. You are just sensitive to the vibrations somehow."

"I always thought I was a very insensitive woman, brutal almost."

Andy raised her eyebrows. "You? You're a good actress maybe, but you are the most sensitive person I know, and the most cultured."

"Then perhaps I've just overdone it, gazing into Renaissance pictures too much. Too much Monteverdi."

"But I felt it too, remember. It wasn't just subjective. Something definitely happened. I don't think we can understand it right now. I think we just have to ponder on it. And maybe get some supper inside us. One thing I do know is that you're not yourself when you're hungry."

The waiter returned with their coffees and water, and they asked him for a menu. Miranda went for a spaghetti carbonara, with enough eggs and cream to weigh down a baby elephant, and Andy chose the sea-food linguini.

"Perhaps it was jet-lag after all," pondered Miranda, as they slowly finished their food. "It can play tricks with your brain."

"I only said that to reassure Maggie. We've been in Italy for eight days now. How are you feeling now, anyway? Your colour has returned."

"Much better, darling, really. And my head isn't tingling at all."

"It was a very weird thing, that's all I can say."

"Yes, very weird. But rather magical as well. I can't begin to understand it. Shall we finish with a gelato?"

"Is there a flavour you've not tried yet?"

"Yes, pistachio, and damson."

"Go on then. I won't tell."

"Thank you darling. You know I do love you."

"I love you as well, Miranda, from the toe of your boots to the top of your beautiful silver head."

Miranda smiled and felt reassured. She didn't want Andy to think she was being forced into marrying a mad woman.

"I'll find out if they have pistachio then."

And she beckoned to the waiter.