utside room, which has long since disappeared; the walls are
very thick. My uncle doubtless caused this door to be taken off its
hinges, and the safe placed in the aperture, the rest of which he then
bricked up.'

'Quite so,' said I, endeavouring to conceal my disappointment. 'As
this strong box was bought second-hand and not made to order, I
suppose there can be no secret crannies in it?'

'It looks like a common or garden safe,' reported my assistant, 'but
we'll have it out if you say so.'

'Not just now,' I replied; 'we've had enough of dynamiting to make us
feel like housebreakers already.'

'I agree with you. What's the next item on the programme?'

'Your uncle's mania for buying things at second-hand was broken in
three instances so far as I have been able to learn from a scrutiny of
these accounts. About four years ago he purchased a new book from
Denny and Co., the well-known booksellers of the Strand. Denny and Co.
deal only in new books. Is there any comparatively new volume in the
library?'

'Not one.'

'Are you sure of that?'

'Oh, quite; I searched all the literature in the house. What is the
name of the volume he bought?'

'That I cannot decipher. The initial letter looks like "M", but the rest
is a mere wavy line. I see, however, that it cost twelve-and-sixpence,
while the cost of carriage by parcel post was sixpence, which shows it
weighed something under four pounds. This, with the price of the book,
induces me to think that it was a scientific work, printed on heavy
paper and illustrated.'

'I know nothing of it,' said the earl.

'The third account is for wallpaper; twenty-seven rolls of an
expensive wallpaper, and twenty-seven rolls of a cheap paper, the
latter being just half the price of the former. This wallpaper seems
to have been supplied by a tradesman in the station road in the
village of Chizelrigg.'

'There's your wallpaper,' cried the youth, waving his hand; 'he was
going to paper the whole house, Higgins told me, but got tired after
he had finished the library, which took him nearly a year to
accomplish, for he worked at it very intermittently, mixing the paste
in the boudoir, a pailful at a time as he needed it. It was a
scandalous thing to do, for underneath the paper is the most exquisite
oak panelling, very plain, but very rich in colour.'

I rose and examined the paper on the wall. It was dark brown, and
answered the description of the expensive paper on the bill.