the name of the visitor i expected, and who hopped up the stairs which led to my chambers half an hour after i entered them, was bob tucker. he is a friend of mine, with plenty of money at command, and has no need to work for a living; but he has a fad, if i may so express it. this fad lay in the detective line, and to give him a job in that direction was to bestow a favor upon him. he entered upon it con amore, and pursued it with a zest never to be found in the professional, who works by the job, or the hour, or the day. he has often said to me that if he were to lose his money he would start an office of his own and lead a jolly life. whether that meant a jolly life to others is a doubtful point. anyway, he is an enthusiastic young fellow of about six and twenty, and is never so happy as when he can adopt a disguise and hunt something or somebody down. he objects to be called robert, which he insists is not his proper name. he distinctly remembers, he avers, being christened bob, so bob tucker he is to all his friends. so far as i am personally concerned, this is convenient to me, my name being robert, which i prefer to bob.

i had foreseen the likelihood of the failure of the search upon which i had entered with emilia, and the surer arrow in my quiver to which i referred when i spoke to emilia about returning to london was dr. peterssen. it was my intention, if all else failed, to break a lance with him, directly or indirectly, and with this object in view i had instructed bob tucker to find out where he lived, what kind of establishment he kept, what his neighbors thought of him, the character he bore, and, in short, anything and everything about his establishment which could possibly be learned. bob was delighted with the task, and undertook it eagerly.

"does he live in london?" he asked.

"don't know," i answered.

this increased bob's delight, and he said he would show me something when he made report to me. of course i told him all i knew of the man, and that he had charge of at least one patient who was not in his right mind.

"well, bob?" i said, on this evening.

"give me a drink first," was bob's rejoinder.

i gave him one, and took one myself. we clinked our glasses and emptied them. then bob lit a cigar, and so did i.

"ready?" said he.

"quite ready," said i.

"keeps a private madhouse," said bob.

"queen anne's dead," said i.

"has more than one patient."

"has three. a man, or gentleman, and two children."

"children?"

"children. prefers them. less trouble. besides, longer expectations with young 'uns. more time for them to grow old."

"true," said i. it will be observed that it was a speciality of bob's to speak in short sentences.

"man, or gentleman," continued bob, "harmless. gentle as a dove. greengrocer's boy told me. sees him sometimes. in the grounds. pities him."

"how old is this poor gentleman, bob?"

"forty, perhaps. forty-five, perhaps. not more than fifty at the outside. hair quite gray, but youngish face."

"where is this private madhouse, bob?"

"sheldon. forty-three miles from london. population seven hundred and thirty. two beerhouses. shut at ten."

"has the establishment a name?"

"tylney house. enclosed. stone wall all round it. easy to get over in one part. all the other parts, broken glass at top."

"character?"

"difficult to get at. population has no opinions. i should say, damned scoundrel."

"why should you say so?"

"impression."

"is dr. peterssen always at home?"

"seldom. away for days together. comes back. stops for a day and a night. goes away again next morning."

"who takes care of tylney house in his absence?"

"keeper, with only one idea. liquor."

"does he take it at the beershops?"

"no. private stock. keeps a dog. savage."

"is anyone admitted to the house?"

"no admittance except on business."

"do many people go there upon business?"

"none. house like a prison."

"is it a large house, bob?"

"largish. room for more."

"more patients?"

"yes."

"look here, bob. i want to tackle this dr. peterssen in some way as yet unthought of, but before i do so i should like to make sure of a certain point. how is it to be done?"

"don't understand you."

"well, this is how it is. i am morally convinced he has something in his house to which he has no claim, and which i would pay a good price to get hold of."

"property?"

"yes."

"portable?"

"yes."

"any objection to say what it is?"

"we're tiled in, bob?"

"honor bright and shining. unless you give consent, not to be mentioned outside this room."

"thank you, bob. the property is a desk."

"buy it of him. my opinion he would sell anything. his own mother if he had one."

"he would not dare to sell it. he would deny that he had ever seen it."

"might bring him into trouble?"

"yes. there are a lot of things hanging to the possession of this desk."

"spirit it away."

"how?"

"get a patient in--a friendly patient. a child for choice. a sharp one it would have to be."

"by jove, bob, you put an idea into my head."

"glad to hear it. act on it."

"you wouldn't mind assisting me?"

"anything in my power."

"you are a trump. but you have been making personal inquiries in the village. if you went down again--supposing you consent to do what i want--you would be recognized."

"not at all. disguise. i'd take old nick himself in, much less dr. peterssen and a parcel of clod-hoppers." (this was a long sentence for bob.) "try me."

"supposing i could find such a friendly patient--a smart little girl who knows her way about--would you go down and arrange that she should be taken care of in tylney house?"

"delighted."

"you've not heard of any cruelties being practised there?"

"no. besides, i should be on the spot. could arrange a system of signals. piece of white paper, with a stone in it, thrown over wall. all's well. piece of blue paper, with a stone in it, thrown over wall. getting frightened. come and take me away. no paper at all thrown over wall. ring the bell and demand to see friendly patient."

"bob, you're a genius."

"thanks. when shall it be?"

"come and see me to-morrow at one."

"i shall be here; to the minute."

he gave me a wink, and after another drink took his departure. he would have stopped longer had i not told him that i had business of importance to attend to, to which he responded, "a wink's as good as a nod," and hastened to say good-night.

the idea he had put into my head was that he should take sophy down to sheldon as a relative of his own, and arrange for her admission to tylney house, and the desk i wished to get hold of was the indian desk of sandalwood, inlaid with silver, which mrs. middlemore had informed me was in m. felix's apartment on the morning of the 16th of january, but which was not there when we searched the rooms a couple of days after. the housekeeper was positive that she saw it on the 16th, and was almost as positive that the police had not removed it. if not they, who? why, dr. peterssen in his interview with m. felix, on the night of the 16th, leaving behind him the snake-shaped dagger which m. felix had thrown at emilia a few minutes later. emilia had repeated to me gerald's words to her with reference to this desk, during their honeymoon in switzerland--"there is a secret drawer in this desk, emilia, and in the desk something which concerns you nearly." what if this should mean the copy of the marriage certificate? in my mind i set it down as meaning it, and i thought, also, that there was a fair chance of finding it in the desk even at this length of time. the secret drawer was known to gerald; emilia, who had used the desk, was not aware of this secret drawer until gerald spoke of it. it might be that gerald's brother did not know of it, and that it had remained all these years undiscovered. granted that the chance was a slender one, still it should not be neglected. i had no compunction in enlisting sophy in the plan i had devised. my moral sense was not blunted, and i felt myself perfectly justified in fighting dr. peterssen with his own weapons. before i sought sophy i thought it necessary to have a few private words with emilia, and i drove at once to my mother's house for that purpose.

"i can stop only five minutes," i said, in excuse of my hurried arrival and departure; "i have a hundred things to attend to to-night." i beckoned to emilia, and she followed me to an unoccupied room. "i wish you," i said to her, "to bend your mind most earnestly on the night of the 16th of last month. don't tremble; there is nothing to be frightened at; i am hard at work in your interests, and i am full of hope. are you quite calm?" she nodded, and i continued. "you saw dr. peterssen go into the house in gerard street; you saw him come out of it. when he went in did he carry a parcel with him?"

"no."

"you are sure of it?"

"i am sure i should have noticed it. i had perfect control over myself, and nothing escaped my attention."

"when he came out of the house did he have a parcel with him?"

"yes, now you mention it, i remember that he did. i attached no importance to it at the time, my mind being bent upon my own errand."

"that is all i wish to know at present. keep a stout heart. all may yet be well."

so, with a bright smile, i left her, and bade the cabman drive to gerard street, soho.