He returned into the front room,—­I at his heels.  That certainly was empty,—­and not only empty, but it showed no traces of recent occupation.  The dust lay thick upon the floor,—­there was that mouldy, earthy smell which is so frequently found in apartments which have been long untenanted.

‘Are you sure, Atherton, that there is no one at the back?’

’Of course I’m sure,—­you can go and see for yourself if you like; do you think I’m blind?  Jehu’s drunk.’  Throwing up the sash he addressed the driver.  ’What do you mean with your old gent at the window?—­what window?’

‘That window, sir.’

‘Go to!—­you’re dreaming, man!—­there’s no one here.’

’Begging your pardon, sir, but there was someone there not a minute ago.’

’Imagination, cabman,—­the slant of the light on the glass,—­or your eyesight’s defective.’

’Excuse me, sir, but it’s not my imagination, and my eyesight’s as good as any man’s in England,—­and as for the slant of the light on the glass, there ain’t much glass for the light to slant on.  I saw him peeping through that bottom broken pane on your left hand as plainly as I see you.  He must be somewhere about,—­he can’t have got away,—­he’s at the back.  Ain’t there a cupboard nor nothing where he could hide?’

The cabman’s manner was so extremely earnest that I went myself to see.  There was a cupboard on the landing, but the door of that stood wide open, and that obviously was bare.  The room behind was small, and, despite the splintered glass in the window frame, stuffy.  Fragments of glass kept company with the dust on the floor, together with a choice collection of stones, brickbats, and other missiles,—­which not improbably were the cause of their being there.  In the corner stood a cupboard,—­but a momentary examination showed that that was as bare as the other.  The door at the side, which Sydney had left wide open, opened on to a closet, and that was empty.  I glanced up,—­there was no trap door which led to the roof.  No practicable nook or cranny, in which a living being could lie concealed, was anywhere at hand.

I returned to Sydney’s shoulder to tell the cabman so.

’There is no place in which anyone could hide, and there is no one in either of the rooms,—­you must have been mistaken, driver.’

The man waxed wroth.

’Don’t tell me!  How could I come to think I saw something when I didn’t?’

’One’s eyes are apt to play us tricks;—­how could you see what wasn’t there?’

’That’s what I want to know.  As I drove up, before you told me to stop, I saw him looking through the window,—­the one at which you are.  He’d got his nose glued to the broken pane, and was staring as hard as he could stare.  When I pulled up, off he started,—­I saw him get up off his knees, and go to the back of the room.  When the gentleman took to knocking, back he came,—­to the same old spot, and flopped