That the house was being watched he did not doubt.  In fact, he no longer believed subterfuge to be of any avail.  He was dealing with dangerously accomplished criminals.  How clever they were he had yet to learn; and it was only his keen intuitive which at this juncture enabled him to score a point over his cunning opponents.

He walked quite openly up the dilapidated steps to the door of No. 236, and was about to seize the dirty iron knocker when the door opened suddenly and a girl came out.  She was dressed neatly and wore a pseudo fashionable hat from which a heavy figured veil depended so as almost to hide her features.  She was carrying a bulging cane grip secured by a brown leather strap.

Seeing Harley on the step, she paused for a moment, then, recovering herself: 

“Ellen!” she shouted down the dim passageway revealed by the opening of the door.  “Somebody to see you.”

Leaving the door open, she hurried past the visitor with averted face.  It was well done, and, thus disguised by the thick veil, another man than Paul Harley might have failed to recognize one of whom he had never had more than an imperfect glimpse.  But if Paul Harley’s memory did not avail him greatly, his unerring instinct never failed.

He grasped the girl’s arm.  “One moment, Miss Jones,” he said, quietly, “it is you I am here to see!”

The girl turned angrily, snatching her arm from his grasp.  “You’ve made a mistake, haven’t you?” she cried, furiously.  “I don’t know you and I don’t want to!”

“Be good enough to step inside again.  Don’t make a scene.  If you behave yourself, you have nothing to fear.  But I want to talk to you.”

He extended his arm to detain her.  But she thrust it aside.  “My boy’s waiting round the corner!” she said, viciously.  “Just see what he’ll do when I tell him!”

“Step inside,” repeated Harley, quietly.  “Or accompany me to Kennington Lane Police Station—­whichever you think would be the more amusing.”

“What d’you mean!” blustered the girl.  “You can’t kid me.  I haven’t done anything.”

“Then do as I tell you.  You have got to answer my questions—­either here or at the station.  Which shall it be?”

He had realized the facts of the situation from the moment when the girl had made her sudden appearance, and he knew that his only chance of defeating his cunning opponents was to frighten her.  Delicate measures would be wasted upon such a character.  But even as the girl, flinging herself sullenly about, returned into the passage, he found himself admiring the resourcefulness of his unknown enemies.

A tired-looking woman carrying a child appeared from somewhere and stared apathetically at Harley.

Addressing the angry girl:  “Another o’ your flames, Polly?” she inquired in a dull voice.  “Has he made you change your mind already?”

The girl addressed as “Polly” dropped her grip on the floor and, banging open a door, entered a shabby little sitting room, followed by Harley.  Dropping onto a ragged couch, she stared obstinately out of the dirty window.