It was alarming news.

He nodded. ‘One of my parishioners overheard some of the English soldiers discussing how they were to be deployed guarding the docks outside the town, on the further banks of the Zee.’

‘Aye,’ I said slowly. ‘I do not suppose Parma will want to find himself caught up in a fight by coming too close to Amsterdam itself. Now that the Spanish fleet is on its way he will want no distractions.’

I pondered this news as I left the church. Parma would need both weapons and transport. Access to both would be difficult for him, though by now he must have commandeered every suitable barge in the Spanish Netherlands. Ettore had pointed out how convenient Cornelius Parker’s legitimate activities would be as a cover for smuggling arms to Parma. As a merchant with vessels of different sizes at his disposal, he might also be intending to supply barges. Every river and canal in this water-logged country thronged with barges. I had seen for myself the daily activity in the town, with barges being loaded and unloaded beside the merchants’ houses standing along the canals. The barges moved up and down the canals all day long, some with sails and oars, some only with oars, both within the town and out into the surrounding countryside. No one ever gave them a second glance.

I found that my feet had taken me around the corner of the church and down the narrow alleyway towards Hans’s pitiful cottage. In the snowy winter months the place had seemed no worse than shabby and poor, but now in the height of summer, the alley stank like a sewer. The narrow kennel running along the centre of the cobbled way was intended to carry waste down to a canal that I could see at the far end of the alley, but it was blocked now with nameless rubbish. This had dammed up the flow of the contents of piss-pots which had been emptied into the alley and which had now spread in a stinking pool across the cobbles. I picked my way round it, holding my breath. On my previous visit I had been impressed by the cleanliness of Amsterdam, but this place was as filthy as any back-alley in London.

The last house on the left, Hans’s old cottage, looked more derelict than ever. No one could be living in it now, not even a beggar, for there were great holes in the thatched roof. Most of the houses here in the town, even quite modest ones, were roofed in terracotta tiles, but this ruined place must be a relic of some older time. I averted my eyes as I passed it, remembering with a shudder the moment when I had found Hans’s body, its throat cut, lying in a pool of frozen blood.

I came out of the alleyway into bright sunlight and there at my feet was yet another of the town’s many canals. There were no grand merchants’ houses here, though a line of a dozen barges lay moored along the canal bank. Just round the corner from the derelict cottage there was another similar building – single-storied, small and dirty, and with a thatched roof, although this one was intact. The single window was shuttered. Considering its look of poverty, it was strange to see that it had a stout new door. And the stout new door was secured by an elaborate lock, clearly also new and shiny, with a lock plate as long as my hand. Curious.

This remote part of the town seemed almost deserted, though I noticed a group of four men walking toward me along the edge of the canal. There was no reason to suppose them in any way unfriendly, but my scalp prickled at the sight of them, walking so purposefully towards me, or perhaps towards that heavily secured building. I withdrew into the alley again and walked rapidly back to the church, then on to my inn.

The next day, still having heard nothing from Ettore, I decide to investigate that remote canal further. I did not return to the point where I had found it before. Something warned me to stay away from the locked hut. Instead I found the canal easily enough by turning down the other side of the church and walking parallel to Hans’s alley, along another street which was wider and cleaner. At this point there were no moored barges and indeed this canal, one of the smaller ones, seemed hardly used at all. For the most part, the buildings along the waterside turned their backs on it. As I followed it in the direction that would lead me out of the town, the canal was on my left hand, while on my right for most of the way there was a blank run of brick walls enclosing gardens of houses which faced in the opposite direction, towards a pleasanter part of the town. Finally I came to a large warehouse where a few men were working. Beyond that the canal wandered off into the countryside, heading roughly west of south and soon disappearing amongst dense reed beds.

I wonder, I thought. If a man wished to move barges quietly out of the town, would there be any better way than this? But perhaps this canal does not go anywhere. It may simply be one of those that the Hollanders dig to drain their fields.

The paved path which had accompanied the canal to this point petered out, though it was possible to follow the line of water further, along a strip of beaten earth through the reed beds, running parallel to the canal but about two yards from it. Perhaps it was one of the jaagpaden, as Captain Thoms had called them, used by men or horses towing barges. I headed slowly along it for perhaps half an hour, through deserted countryside, encountering no one. There was no sound but the soft incessant whispering of the reeds in the slight breeze and the occasional call of a bird. I disturbed a heron who made off with those long, slow wing beats which look too casual to lift the heavy body and trailing legs, yet somehow manage to propel the bird effortlessly upwards. I sat down on the ground, watching it fly as far as the nearest tree, a pollarded willow. There were few enough trees in this flat country of reeds and water, but from a bundle of twigs perched amongst its branches, I guessed that the heron had its nest there.

The silence and the warmth of the midday sun stole over me, so that I lay down on my back amongst the reeds, watching, through half-closed eyes, a grasshopper clinging, above my head, to a swaying stem. The reeds were alive with the leaping of these small green grasshoppers and the faint chirp of crickets, almost on the edge of hearing. Sleep was stealing over me, when the grasshopper above my head suddenly sprang from the stem and disappeared. At the same moment the heron, who must have made a silent return, clattered up from the edge of the canal. Suddenly I was aware of what they had heard, the sound of oars and men’s quiet voices.

I rolled over on my stomach and peered through the reeds. At first I could see nothing, then a barge came into sight, rowed by four men and towing another larger one. The sails were furled, for there was not enough of a breeze to aid their labours. Between the two pairs of oarsmen lay a bundle in canvas, perhaps a yard or more long and about as large around as my arms would reach. The following barge was piled high with more bundles, all the same size and shape. In its stern there were three large barrels.

Giving thanks that the reeds were thick here, I pressed my head down against the ground, my left cheek painfully against a sharp stone. My clothes were dull in hue and unlikely to draw attention amongst the reeds unless one of the men were to turn and look in my direction. With the instinct of a hunted animal seeking sanctuary, I closed my eyes and held my breath, until I could no longer hear the sound of the oars and the heron had returned to his fishing.

Slowly I sat up. The sunlight reflected off the water of the canal danced in stars before my eyes. Those canvas bundles meant only one thing to me. I had seen similar ones in Dover Castle. They contained army muskets, half a dozen in each. The barrels might be anything, but my guess was gunpowder or shot. As for the barges, I recognised the leading one by a careless streak of green paint across the bow. I had last seen it outside the locked hut, no more than a few yards from Hans’s door.