mply walked past us--probably on the other side of
the road--as we stood waiting for the omnibus, and turned up Kennington
Park Road. She probably guessed that we were waiting for the omnibus and
walked up the road in the direction in which it was going. Presently the
omnibus would pass her, and there were you in full view on top keeping a
vigilant look-out in the wrong direction. Then she would quicken her
pace a little and in a minute or two would arrive at the Kennington
Station of the South London Railway. In a minute or two more she would
be in one of the electric trains whirling along under the street on
which your omnibus was crawling. She would get out at the Borough
Station, or she might take a more risky chance and go on to the
Monument; but in any case she would wait for your omnibus, hail it and
get inside. I suppose you took up some passengers on the way?"

"Oh dear, yes. We were stopping every two or three minutes to take up or
set down passengers; and most of them were women."

"Very well; then we may take it that when you arrived at the Mansion
House, Mrs. Schallibaum was one of your inside passengers. It was a
rather quaint situation, I think."

"Yes, confound her! What a couple of noodles she must have thought us!"

"No doubt. And that is the one consoling feature in the case. She will
have taken us for a pair of absolute greenhorns. But to continue. Of
course she travelled in your omnibus to Kensington--you ought to have
gone inside on both occasions, so that you could see every one who
entered and examine the inside passengers; she will have followed you to
Endsley Gardens and probably noted the house you went to. Thence she
will have followed you to the restaurant and may even have lunched
there."

"It is quite possible," said I. "There were two rooms and they were
filled principally with women."

"Then she will have followed you to Sloane Street, and, as you persisted
in riding outside, she could easily take an inside place in your
omnibus. As to the theatre, she must have taken it as a veritable gift
of the gods; an arrangement made by you for her special convenience."

"Why?"

"My dear fellow! consider. She had only to follow you in and see you
safely into your seat and there you were, left till called for. She
could then go home, make up for her part; draw out a plan of action,
with the help, perhaps, of Mr. Weiss, provide herself with the necessary
means and appliances and, at the appo