THE moon is high in the sky, its weak, pale light filtered by mist and covering the fields with a purple-blue wash. It is all-embracing, as if some heavenly artist has been at work with a giant paintbrush.

There is a compelling urge to stare, but there is no time to gaze out of the car window on this midnight journey. For my companion and I have lost our way and we must find a certain town that will be the key to us arriving at our destination before the birds find their voices.

We travel through village after village. If only we had taken that turn to the right on the outskirts of Arras. Now we are travelling across a landscape that is strangely reminiscent of Lincolnshire or the Fens. It is rolling country, dotted with the outlines of woods, lights in the far distance betraying a farmhouse or wayside cottage.

We stop the car to examine a map with the aid of a torch. The night is deathly quiet, save for the sound of an animal rustling through the leaves in the woods. We must find this place at all costs. The car starts off down the road again.

Suddenly, a sign appears. Bapaume. We have found it at last. Now it will be plain sailing for the rest of this nocturnal odyssey across the old battlefields of the Somme.

This is my seventh trip to the Western Front and I'm here with colleague Mark Higgitt to do some research. As the car glides down the old Roman road to Albert, we start to talk about ghosts and wonder if those slaughtered legions of 1916 still haunt these chalk uplands, spirits that remain ever-young, permanent guests in the fields of Picardy.

The signposts read like battle honours on the colours of the old county regiments. Warlencourt, Courcelette, Martinpuich... Bazentin, Contalmaison. Pozieres, Thiepval... Mametz and Montauban. And somewhere out in the gloom is Trones Wood, where the Northamptonshire Regiment was shot to pieces in 1916.

There, in this hell of shot, shell and zipping bullets, great-uncle Ernest somehow managed to pull through. It beggars belief how any British soldier could have survived the Retreat From Mons, the Marne, the Aisne, First Ypres... and the Somme. But, incredibly, some did. And he was one.

But the question was about ghosts. No, I've never come across anything in my travels along the old battle lines, tell Mark. In fact, the overwhelming sensation is one of peace. Whether its Sanctuary Wood on the Ypres Salient or the Chemin des Dames near Soissons on the Aisne there's never been the feeling of a presence or the sensation of being in the company of spirits.

The conversation changes tack and soon we are in Auchonvillers, where we are about to go into billets courtesy of a charming couple called Michael and Julie Renshaw.

Author Michael is an authority on the war and Julie runs a guest house that is a firm favourite with British people who are being drawn to the battlefields in increasing numbers. Our stay will prove to be interesting in more ways than one. But for the time being, we can only think of having that much-needed sleep.

So, we must wait for the next night for our conversations. And over a sumptuous dinner, I ask him about the ghosts of the Somme.

After all, autumn is approaching and the house in which we are sitting is built over a trench that was occupied by the Middlesex Regiment on that fateful July 1, 1916.

I tell Michael about Bob and Marilyn, a couple from Perry Barr whom we had met that day. Bob, merrily puffing away on his pipe, had let it slip almost casually that he knew of a photograph taken in Trones Wood, which, when developed, showed the unmistakable image of a soldier in combat.

Oh yes, said Michael. I remember once being lost in Trones Wood. Definitely a very strange feeling. Not very nice at all. This is where I found the German soldier's dog tag.

Michael left the table and fetched the tag, a weathered sliver of alloy, wafer-thin yet still bearing a name. What was the story attached to this, we wonder.

Our host tells us of how, after finding the object, he stored it on the shelf of a caravan in which they were living. His daughter was staying in the vehicle and in the morning reported that a young man had been in the room during the night, leaning over her, as if searching for some item on the shelf above her head.

In her drowsiness, she had assumed it was a member of the family. This mysterious figure, with short-cropped blond hair was dressed in what appeared to be a grey uniform. Yet there was no sense of menace, for the man was smiling.

She told the story to her father who suddenly realised where he had hidden the dog tag. Its owner had returned to search for it...

More followed. Michael showed us another dog tag, with the left-hand portion missing.

He explained how he had discovered this item in Mametz Wood, which lies halfway between Albert and Combles. The piece of alloyed metal bore the legend Diehl, Wiesbaden. Michael allowed the guests to pass the object around the table. Then, the punchline. For exactly a year later, he had been walking in the wood when an object perched on top of a tree root caught his eye. He picked it up it was the missing half to the dog tag that had had found 12 months before.

We are now becoming gluttons for punishment. What about this house, Michael, ventures one of our company, peering behind the half-empty bottle of Cabernet. You know, being built over an old trench line and all that...

Oh, you mean the soldiers marching through the bedroom, says Michael, with more than the hint of a glint in his eye. Yes, but which bedroom is that, asks the man on a walking holiday, now sinking into his seat.

Well, it's not the one across the way, so that just leaves the one on the left... the room where you are.

There is now some good-natured leg-pulling and banter. Nevertheless, the men of 1916 are apparently regular visitors. The strangest manifestation was of 12 soldiers "in a ball of light" an occurrence that for some reason did not unduly disturb the person who witnessed it.

We should not be surprised by tales as tall as these, for all around us are the sites of battle.

But whether you're a sceptic or not, one thing cannot be denied. For if there is such a thing as ghosts, then if there is anywhere they are likely to exist, it is here on the Somme.