Describe the incident with the “ghost prints”.

From the text:

“I looked down and saw the youngsters had stopped and were gaping at the muddy footmarks I had left behind me up the newly whitened steps. The passing people elbowed and jostled them, but their confounded intelligence was arrested. ‘Thud, thud, thud, when, thud, shall we see, thud, his face, thud, thud.’ ‘There’s a barefoot man gone up them steps, or I don’t know nothing,’ said one. ‘And he ain’t never come down again. And his foot was a-bleeding.’

“The thick of the crowd had already passed. ‘Looky there, Ted,’ quoth the younger of the detectives, with the sharpness of surprise in his voice, and pointed straight to my feet. I looked down and saw at once the dim suggestion of their outline sketched in splashes of mud. For a moment I was paralysed.

“‘Why, that’s rum,’ said the elder. ‘Dashed rum! It’s just like the ghost of a foot, ain’t it?’ He hesitated and advanced with outstretched hand. A man pulled up short to see what he was catching, and then a girl. In another moment he would have touched me. Then I saw what to do. I made a step, the boy started back with an exclamation, and with a rapid movement I swung myself over into the portico of the next house. But the smaller boy was sharp-eyed enough to follow the movement, and before I was well down the steps and upon the pavement, he had recovered from his momentary astonishment and was shouting out that the feet had gone over the wall.

“They rushed round and saw my new footmarks flash into being on the lower step and upon the pavement. ‘What’s up?’ asked someone. ‘Feet! Look! Feet running!’

“Everybody in the road, except my three pursuers, was pouring along after the Salvation Army, and this blow not only impeded me but them. There was an eddy of surprise and interrogation. At the cost of bowling over one young fellow I got through, and in another moment I was rushing headlong round the circuit of Russell Square, with six or seven astonished people following my footmarks. There was no time for explanation, or else the whole host would have been after me.

“Twice I doubled round corners, thrice I crossed the road and came back upon my tracks, and then, as my feet grew hot and dry, the damp impressions began to fade. At last I had a breathing space and rubbed my feet clean with my hands, and so got away altogether. The last I saw of the chase was a little group of a dozen people perhaps, studying with infinite perplexity a slowly drying footprint that had resulted from a puddle in Tavistock Square, a footprint as isolated and incomprehensible to them as Crusoe’s solitary discovery.