Philippe, let me encourage you to come to England! The women here are delightful beyond imagining!

[Letter from Louis de Glabre to his friend Philippe Froidevaux, 16 January 1737]

'Watch out!' Esther cried.

I ducked, and my feet went out from under me. I slid in the snow, flailed wildly and ended up flat on my back. The snowball flew over my head.

Fat flakes of snow pattered wetly on to my face and clogged my eyelashes; blinking, I looked up at the dark night sky. Perhaps this hadn't been a good idea.

Esther was giggling as she bent to help me up. Her fair hair was coming loose under her hat, and her greatcoat was splattered with patches of snow where my aim had been better than hers. My wife; my lady wife, with generations of stern ancestors behind her, and a reputation as a sensible, middle-aged woman, was scandalously wearing breeches, and throwing snowballs. And I'd worried over the twelve years' difference between us, thinking she'd find me a callow youth!

'Are you all right, Charles?'

I sat up, feeling the wet soaking through my coat, and my shirt and my breeches. Even in the swirling blizzard, I could see the heightened colour in Esther's cheeks, the excited glow in her eyes. I was relieved; she'd not been feeling well recently.

'No,' I said grumpily. 'I'm not all right.' How would the ladies and gentlemen of the town – my customers – react if they saw me at this moment. Respectable musicians do not roll in the snow like children. I scrambled up. 'Why did you throw a snowball and then tell me to duck!'

'I didn't throw it!' she said, with laughing indignation. 'Hugh did!'

The flakes were coming down faster and thicker, veiling everything around us with a thick curtain of white. Obscuring the deserted Key: the tall buildings, the chandlers' shops, the taverns and the brothels, the printing office. Ships at the wharves had snow on every line of the rigging, and were sitting in a thin layer of ice as the River Tyne froze at the edges; the tidal flow kept the centre running though sluggish. The bell of All Hallows' church struck midnight. Sunday. That made it worse; Sunday is supposed to be a day of pious restraint.

I couldn't see Hugh anywhere. Hugh Demsey, dancing master, who'd just put me on my back in the snow. This expedition had been his idea. We'd originally intended to spend a quiet Saturday evening at home in Caroline Square, over dinner and wine, with music and conversation afterwards. My wife, myself, and my closest friend. Comfortable, cosy entertainment for a cold January night. But that was before Hugh glanced out of the window and said, 'Good Lord, it's snowing!'

In the week or two since Christmas, we'd had an entire week of heavy frosts, and temperatures so cold no one wanted to venture out of doors. The snow had been bound to follow. 'Let's go out and have a slide,' Hugh said enthusiastically. Looking at the gently falling flakes, I'd remembered the winters of childhood, sledging and sliding and skating, and throwing snowballs ...

I spotted Hugh at last, a dark shadow in the blizzard; I grabbed up a handful of snow and squeezed it hard. I'd have to be careful; Hugh was standing at the edge of the river and I didn't want to knock him in. I sauntered up to him, arm behind my back. If only Esther didn't give me away with her giggling!

Hugh swung round. His hat had come off and his black hair slapped about his face. Even the voluminous greatcoat couldn't disguise the handsome figure the ladies so admired – dancing masters rarely get fat. 'Look at this!' He pointed down into the river.

It must be a trick; I said, 'No, you don't get me that way!' but he'd already turned back. Esther peered over his shoulder into the driving snow that obscured the water below. I kept a safe distance, just in case, and followed their gaze.

The tide was out, exposing ice-crusted mudbanks below the wharfs. Two lanterns burned in the darkness, apparently hanging in the middle of the river. In reality, they were on the shops on the Tyne Bridge of course; I could just make out the bridge's high arches and the dark hulks of the houses. Snow swirled in again.

'The second arch,' Hugh said. 'There's something hanging down.'

He was right. A faint whitish line seemed to be written on the bridge, dropping down the pier from one of the shops to the mudflat below. A rope – and someone was climbing down it.

'An elopement!' Esther said, delighted. 'I had half a mind to do something similar myself, Charles!'

Esther and I have been married five months now and society is, just, beginning to accept the situation. An alliance between a man of twenty-seven and a woman of thirty-nine is bound to be frowned upon, particularly when the woman has money and status, and the man is a mere musician. No one, apparently, believes that it can be a matter of love. There was a time when I set my mind against all idea of marriage, for fear of the damage it might do to Esther's reputation. She herself was equally determined to marry me.

The matter hadn't required an elopement to settle it, however. Ours was a 'forced' marriage; my patron found us in a compromising position. That is to say, we were standing decorously a good six feet apart, but the room was a bedroom, which makes all the difference. I have long been extremely glad of the way matters turned out.

'We ought to do something,' I said, uneasily eyeing the figure on the rope.

'Don't be such a prig, Charles!' Hugh said. 'You're spoiling the romantic moment!'

Esther cautiously strained to look down at the mud flats. 'I cannot see an earnest lover.'

The snow danced in closer, blowing into our faces, obscuring our view. I squinted against the flying flakes, at the figure sliding down the rope. A woman, wearing skirts and struggling with them. She should have copied Esther and opted for a pair of breeches. The figure hung for a moment by one hand, then let go, dropping the last few feet to land on hands and knees on the mudbank.

'Mud is not romantic,' Esther said regretfully.

The woman scrambled to her feet, hauling up her skirts. She looked lithe and active, obviously young, and certainly not weighed down by anything as prosaic as luggage.

The thick snow swirled in again. 'We should do something,' I said uncertainly. I caught glimpses of the figure struggling through the mud towards the landing steps up on to the Key. There was no impatient lover in sight. 'It might not be an elopement. She might be a thief – stealing from one of the shops on the bridge ...'

Esther and Hugh broke into protests at the same time. Hugh grabbed my arms and turned me round, away from the bridge. 'No, no!' he said. 'Not a thief.'

'This is not another crime,' Esther said, firmly. 'Or, if it is, it is a small one, and we need not worry about it. Time to go home.'

'That's right,' Hugh said. 'Go home. Have a nice sleep. Forget all about it.'

'Yes,' Esther said, wickedly. 'Sleep – just what I was thinking of.'

I sighed. Over the past two years, I've somehow become embroiled in five murders – not in the least my fault – and now Hugh and Esther persist in thinking I see death and disaster everywhere. 'I'm not thinking of taking a hand in it myself! We could call out the Watch.'

'They won't come out!' Hugh said. 'Not in this weather! Besides, do you want them to see your...