Despite the wind and heavy cloud there is a moon, reflected when it appears off standing water in the fields. Silver streaks beyond the roadside hedges. It’s wet out there, good footwear needed.

Looking north, the land drops just a few feet as the sea moves to greet it. It’s a 10,000 year old dance. Caught between the two, there is both salt and fresh marsh. An intertidal shift of sands and mud, shingle and dunes. There are vast resources of soft sediments out there beneath the shallow waves, horizon stretching lands that have only just been lost under the grey lines and tides.

It is an advance and retreat landscape. Always moving, the past revealed at the lowest of low tides when you stumble across fallen pine trees wedged between the rock pools.

Mud, the 1888 OS map says. And, Remains of Ancient Forest. Mud and good boots. Head torches and distant voices. Here is the meet up, the hasty words of welcome and the desire to get out there, into the dark, into the wild and on to the secret paths. The places they don’t open up to people every day. Out there where there is more mud and distant waves from the beach beyond. Cold pinching, hands clenching and unclenching against the chill.

Off the boardwalks, onto the wet ground. Mud and, sometimes, old ordnance, she says. Old tank tracks followed out to the middle of it all. Standing in the spots that are normally distant, way distant, far over there. In the depth of the quiet hidden now. The gloom thins. The moon is gently receding. We whisper to one another, guided into the hide.

The first harrier rises out of the reeds like a drone, straight up, fuh-fuh-fuh-fuh. Straight up. Borne swiftly and with sudden presence into the grey and sleepy morning.

A singularity of feathers and motion. The expanse of air above it, that vast Norfolk sky, seems to pull it up.

All air itself, all flurry and flash. A whisper of bird.

It’s only yards away and for a second hovers, wings and breeze, that’s all it is, just wings and breeze, catching the breath of coast-cold before it yaws and sweeps away, far across the marsh. There barely long enough for you to acknowledge it even, to blink uncomprehendingly.

Even though, ridiculously, even though this is what you came for.

Your brain runs after it, unsteady and stumbling, as it vanishes elegantly over the straight lines and the blur, while you are already failing to catch up. And this is what you came for.

It’s the suddenness that gets you. That lurch forwards, a realisation. The razor cold immediacy of the bird suddenly there.

But they are always like that. Marsh harriers catch you unawares. It should say that in the guides. There should be a symbol for it.

I am not able to plan these things normally. The birds – almost all the fantastic birding experiences I’ve had – just happen to me not me to them. And even now, this is supposed to be expected, this experience. Booked and timetabled (although no-one’s told the harriers). Even so, even with that, it’s suddenly, wonderfully there.

Fuh-fuh-fuh-fuh. Another. Straight up. Further away this time, but joltingly just there. That same suddenness. Up and out of the reeds and flying, gliding over towards the hide this time, so fast though. So fast. The harrier covers the distance and is gone over our heads in a moment.

They are a stand and stare bird, marsh harriers. Like barn owls, I just assume that everyone must just stop what they’re doing and gawp at them from the moment you pick them up until the last sparkle and shade disappears. I assume. I assume that’s what happens. How could you not? What else could you be doing; while I’m standing tracking their flight, what else is there to do? You must be doing that too, I assume.

They rise up from the parchment-coloured reeds. Everything is lightening now. More and more of them rising into the air. We count thirty and more. Over the last of the freshwater lagoons before the saltmarsh, five thousand golden plover panic and push, pulsing and surging into the bright new day.