an

darted out of it, like a rabbit out of its burrow.

"capital!" said holmes, calmly. "watson, a bucket of water

over the straw. that will do! lestrade, allow me to

present you with your principal missing witness, mr. jonas

oldacre."

the detective stared at the new-comer with blank amazement.

the latter was blinking in the bright light of the

corridor, and peering at us and at the smouldering fire.

it was an odious face -- crafty, vicious, malignant, with

shifty, light-grey eyes and white eyelashes.

"what's this, then?" said lestrade at last. "what have you

been doing all this time, eh?"

oldacre gave an uneasy laugh, shrinking back from the

furious red face of the angry detective.

"i have done no harm."

"no harm? you have done your best to get an innocent man

hanged. if it wasn't for this gentleman here, i am not

sure that you would not have succeeded."

the wretched creature began to whimper.

"i am sure, sir, it was only my practical joke."

"oh! a joke, was it? you won't find the laugh on your

side, i promise you. take him down and keep him in the

sitting-room until i come. mr. holmes," he continued, when

they had gone, "i could not speak before the constables,

but i don't mind saying, in the presence of dr. watson,

that this is the brightest thing that you have done yet,

though it is a mystery to me how you did it. you have

saved an innocent man's life, and you have prevented a very

grave scandal, which would have ruined my reputation in the

force."

holmes smiled and clapped lestrade upon the shoulder.

"instead of being ruined, my good sir, you will find that

your reputation has been enormously enhanced. just make a

few alterations in that report which you were writing, and

they will understand how hard it is to throw dust in the

eyes of inspector lestrade."

"and you don't want your name to appear?"

"not at all. the work is its own reward. perhaps i shall

get the credit also at some distant day when i permit my

zealous historian to lay out his foolscap once more -- eh,

watson? well, now, let us see where this rat has been

lurking."

a lath-and-plaster partition had been run across the

passage six feet from the end, with a door cunningly

concealed in it. it was lit within by slits under the

eaves. a few articles of furniture and a supply of food

and water were within, together with a number of books and

papers.

"there's the advantage of being a builder," said holmes,

as we came out. "he was able to fix up his own little

hiding-place without any confederate -- save, of course,

that precious housekeeper of his, whom i should lose no

time in adding to your bag, lestrade."

"i'll take your advice. but how did you know of this

place, mr. holmes?"

"i made up my mind that the fellow was in hiding in the

house. when i paced one corridor and found it six feet

shorter than the corresponding one below, it was pretty

clear where he was. i thought he had not the nerve to lie

quiet before an alarm of fire. we could, of course, have

gone in and taken him, but it amused me to make him reveal

himself; besides, i owed you a little mystification,

lestrade, for your chaff in the morning."

"well, sir, you certainly got equal with me on that. but how

in the world did you know that he was in the house at all?"

"the thumb-mark, lestrade. you said it was final; and so

it was, in a very different sense. i knew it had not been

there the day before. i pay a good deal of attention to

matters of detail, as you may have observed, and i had

examined the hall and was sure that the wall was clear.

therefore, it had been put on during the night."

"but how?"

"very simply. when those packets were sealed up, jonas

oldacre got mcfarlane to secure one of the seals by putting

his thumb upon the soft wax. it would be done so quickly

and so naturally that i dare say the young man himself has

no recollection of it. very likely it just so happened,

and oldacre had himself no notion of the use he would put

it to. brooding over the case in that den of his, it

suddenly struck him what absolutely damning evidence he

could make against mcfarlane by using that thumb-mark. it

was the simplest thing in the world for him to take a wax

impression from the seal, to moisten it in as much blood as

he could get from a pin-prick, and to put the mark upon the

wall during the night, either with his own hand or with

that of his housekeeper. if you examine among those

documents which he took with him into his retreat i will

lay you a wager that you find the seal with the thumb-mark

upon it."

"wonderful!" said lestrade. "wonderful! it's all as clear

as crystal, as you put it. but what is the object of this

deep deception, mr. holmes?"

it was amusing to me to see how the detective's overbearing

manner had changed suddenly to that of