bert. 'If that is Ravengar in the photo, and if we
can find out anything to-night, and if Ravengar's in this business'--he
jerked his elbow towards the cylinders--'we shall be so much to the
good. Besides, it won't take us a minute.'

So they went forward, through twilit chambers and passages filled with
sheeted objects, past miles of counters inhabited by thousands of
chairs, through doors whose openings resounded strangely in the vast
nocturnal silence of Hugo's, till they came to the Medical and
Pharmaceutical Department. And the Medical and Pharmaceutical
Department, in its night-garb, and illuminated by a single jet at either
end of it, seemed to take on a kind of ghostly and scented elegance; it
seemed to be a lunar palace of bizarre perfumes and crystal magics.

The two young men halted, and listened, and they could catch the
distant footfall of the patrols echoing in some far-off corridor. That
reassured them. They ceased to fancy the smell of burning and to be
victimized by the illusion that a little tongue of flame darted out
behind them.

Albert gained access to the accountant's cupboard, and pulled out a
number of books, over which they pored side by side.

'Here you are!' exclaimed Simon presently. 'Receipts. January 9.'

And Albert read: 'No. 6,766, Mrs. Poidevin, 37, Prince's Gate; vinolia.
No. 6,767, Dr. Woolrich, 23, Horseferry Road; chloroform! Can't make out
the quantity, but it must be a lot, I should think; the price is
eighteen and ninepence.'

'Dr. Woolrich, 23, Horseferry Road?' Simon repeated mechanically.
'Chloroform?'

'That's it,' said Albert. 'You may bet your boots. Let's look him up in
the Medical Directory, if they've got one here. Yes, they're sure to
have one.'

But there was no Dr. Woolrich in the Medical Directory.

Once more the brothers stared at each other. Was or was not Ravengar
alive? Were they or were they not on his track?

'Listen, Si,' said Albert. 'I'll drive right down to 23, Horseferry
Road, and have a look round. Eh? What do you say?'

'I think I'll come, too,' Simon replied.

In six minutes Albert pulled up the hansom at the end of the street, and
they walked slowly towards No. 23, but on the opposite side of the road.

'That's it,' said Simon, pointing. 'What are you going to do now?
Inquire there?'

At the same moment a window opened behind them, in the house immediately
facing No. 23; they both heard a hissing sound, evidently designed to
attract th