A figure lurking in the shadows in New York City might be a mugger.
In York, one of England's chief historic and religious centers 211 miles north of London, it could be a ghost.
Ghosts are as much "a part of our heritage as the stories of King Arthur, Robin Hood and other-folk heroes," writes John V. Mitchell, a York school teacher, in the introduction to his book "Ghosts of an Ancient City."
York dates back before the Roman invasion in A.D. 72 and was a strategic center for the Roman legions until their withdrawal in the fifth century when they abandoned Britain to the Anglo-Saxon raiders from the Continent.
The city is surrounded, by walls dating from the 14th Century. The upper stories of ancient timbered houses lean precariously toward each other across narrow winding streets.
York is shrouded in medieval mists and haunted by the ghosts of centuries. Ghosts are everywhere in doorways, in the back streets of the town, in churches, in a dancing school.
One in medieval uniform even haunts the night porters in the Viking Hotel.
And while New York City cops are busy tracking down criminals, at least one York constable spends his off hours conducting ghost tours.
Harry Martindale, a tall, handsome man in the traditional bobby uniform, is a vegetarian, a teetotaler and a nonsmoker.
He also is becoming a legend in his own time, written up in books, interviewed on British radio and television, and all because when he was 18 he saw not one ghost, but a whole army of them.
Harry was an apprentice plumber in 1953 when he was sent to install central heating in Treasurer's House, close to York Minster, the huge and magnificent cathedral of St. Peter.
He had barely begun to knock a hole in the four-foot-thick arched ceiling when suddenly, from the wall which was supporting his ladder, out stepped a Roman soldier.
At the time, Harry didn't know that his ladder was resting on an old Roman road, 18 inches below the stone floor of the cellar.
Here's how Harry relayed it recently to a group of American journalists who had descended through a narrow dark passageway to assemble in the same cellar:
"I heard a sound the only way I can describe it is the sound of a musical note. It was just like a trumpet blaring out no tune, just a blare. At the same time, a figure came out of the wall. And the head of the figure was in line with my waist, with a shining helmet.
"I knew that it shouldn't be here and when I say that I was terrified, I mean that I WAS terrified," Harry said, speaking in a rich Yorkshire accent. "I fell off the ladder and scrambled into the corner... and from there I got a bird's eye view of what it was. It was the head of a Roman soldier."
The figure crossed the room at a slight angle and disappeared into the opposite pillar. He was immediately followed by another Roman soldier on horseback, Harry said, and behind the horse, Roman soldiers in twos, walking side by side.
"Now I was in no fit state to count them, but as I say at the time I took a count of between 12 and 20. I was suffering from severe shock, and the immediate relief I got was that not one of them looked in my direction. You couldn't see through them. I saw them exactly as what you i and I are."
The soldiers Harry saw that day were small men, "about 5 feet, in want of a good wash and a shave. Nothing smart about them."
They were dressed in handmade uniforms, Harry said, "like skirts, made of cloth, in various shades of green. "When they came through the wall, I couldn't see even the horse from the knees down. The road had only been excavated in the center of the cellar. The surface is 18 inches below, and I couldn't see them from the feet up until they were walking on the center of the cellar.
"They all had the same helmet on, with the plumes coming out of the back, down the neck. They all carried a short sword on the right-hand side. I used to think that Roman soldiers carried a long sword, but it was like an oversized dagger on the right-hand side.
"The horse I can only describe as a great big cart horse not like the chargers that they use nowadays on the television. And they came as quick as they went.
"When they were in the center of the cellar I could hear like a murmuring. No speech, just a murmuring."
Harry fled from the cellar and collapsed at the top of the stairs, where the old curator found him.
"By the look of you you've seen the Roman soldiers," the curator said. "As soon as he said this," Harry related, "I knew that it hadn't been a nightmare. I knew then that I'd actually seen it."
But for 20 years Harry didn't tell of his strange experience for fear of ridicule.
Recently he discovered that he is the third person known to have seen the soldiers. The second was the old curator, seven years before Harry. The first, an American professor back in the 1930s, seven years before the curator.
"He knew about them, he came, he waited in the cellar, he saw them. Which makes those in York think that lots of people seen them. Cause he knew about them. And he knew to come here and sit.
"There's a fourth person to have seen them. I've been to see this fourth person with John Mitchell. And this chappy whose seen them since me, he is mentally very ill. He refuses to discuss seeing the Roman soldiers."
According to Harry, historians have put a date on the Roman soldiers of A.D. 390.
At that time, Harry said, the Romans were making their own uniforms, completely forgotten by Rome. The bulk of the Roman army had gone back to Italy.
"They left like a police force over here of volunteers and men that married the local women and when they used to go out on patrol they used to have to go out in parties of between 20 and 40, so they wouldn't be ambushed. When they went out they had to go out for at least a week or a fortnight. And when they came back they'd all be tired, scruffy, wanting a shave. Just like these were."
A few months ago, Harry said, a water main burst outside Treasurer's House, and in fixing it the base of a Roman court was unearthed.
"And they know now that where the cellar wall is, is the exact entrance to the Roman garrison."
In the cellar today is television and sound equipment installed by a British newspaper.
According to Harry, within six weeks of putting it in they picked up a sound of mumbling and horses hooves hitting stones.