The unpaved street, undrained and unutterably filthy, was ankle-deep in mud, even at the close of this hot August day.  Down one side a long blank wall, stone-built and green with mildew, presented an unbroken frontage:  on the other the row of houses with doors perpetually barred, and windows whereon dust and grit had formed effectual curtains against prying eyes, added to the sense of loneliness, of insecurity, of unknown dangers lurking behind that crippled archway, or beneath the shadows of the projecting eaves, whence the perpetual drip-drip of soot water came as a note of melancholy desolation.

From all the houses the plaster was peeling off in many places, a prey to the inclemencies of London winters; all presented gray facades, with an air of eeriness about their few windows, flush with the outside wall—­at one time painted white, no doubt, but now of uniform dinginess with the rest of the plaster work.

There was a grim hint about the whole street of secret meetings, and of unavowable deeds done under cover of isolation and of darkness, whilst the great crooked mouth of the archway disclosing the blackness and gloom of the passage beyond, suggested the lair of human wild beasts who only went about in the night.

As a rule but few passers-by availed themselves of this short and narrow cut down to the river-side.  Nathless, the unarmed citizen was scared by these dank and dreary shadows, whilst the city watchman, mindful of his own safety, was wont to pass the mean street by.

Only my Lord Protector’s new police-patrol fresh to its onerous task, solemnly marched down it once in twenty-four hours, keeping shoulder to shoulder, looking neither to right nor left, thankful when either issue was once more within sight.

But in this same evening in August, 1657, it seemed as if quite a number of people had business in Bath Street off the Strand.  At any rate this was specially noticeable after St. Mary’s had struck the hour of nine, when several cloaked and hooded figures slipped, one after another, some singly, others in groups of two or three, into the shadow of the narrow lane.

They all walked in silence, and did not greet one another as they passed; some cast from time to time furtive looks behind them; but every one of these evening prowlers seemed to have the same objective, for as soon as they reached the crippled archway, they disappeared within the gloom of its yawning mouth.

Anon when the police-patrol had gone by and was lost in the gloom there where Bath Street debouches on the river bank, two of these heavily cloaked figures walked rapidly down from the Strand, and like the others slipped quickly under the archway, and made straight for the narrow door on the left of the passage.

This door was provided with a heavy bronze knocker, but strangely enough the newcomers did not avail themselves of its use, but rapped on the wooden panels with their knuckles, giving three successive raps at regular intervals.