penteney strode forward and picked up the telegram; a moment later he passed it over to hetherwick.

"that's most unfortunate!" he exclaimed. "and unexpected, too! of course, the fellow's slipped off to the continent."

matherfield looked over hetherwick's shoulder and read the message.

"followed him down here last night. put up at same hotel, but he slipped me and got clear away early this morning. returning now."

"you should have employed two men, gentlemen," said matherfield. "one's not enough—in a case of that sort. but it's as i said before—this man should have been given into custody at once. however——"

he got up from his chair, as if there was no more to be said, and moved towards the door. but half-way across the room he paused.

"you'll let me know if anybody comes forward about that reward?" he suggested. "it's more of a police matter, you know."

the two partners, who were obviously much annoyed by the telegram, nodded.

"we shall let you know—at once," answered blenkinsop. "of course, you'll regard all we've told you as strictly confidential?"

"oh, to be sure, sir," replied matherfield. "it's not the only private and confidential feature of this affair, i assure you."

outside he turned to hetherwick.

"well!" he said. "we've cleared up a few things, mr. hetherwick—or, rather, those two have cleared them up for us. but are we any nearer answering the question that we want answering—who poisoned robert hannaford?"

"i think we are!" replied hetherwick. "i am, anyhow! either baseverie poisoned him—or he knows who did!"

"knows who did!" repeated matherfield. "ah!—that's more like it. i don't think he did it—he wouldn't be so ready about showing himself forward."

"i'm not so sure of that," remarked hetherwick. "from what we've heard of him, he seems to be a bold and daring sort of scamp. probably he thought he'd have a very easy prey in lady riversreade; probably, too, he believed that a woman who's got all that money would make little to do about parting with thirty thousand pounds. one thing's sure, however—baseverie knows what we want to know. and—he's gone!"

"perhaps—perhaps!" said matherfield. "and perhaps not. this man of penteney's no doubt tracked him to dover, and there he lost him, but that isn't saying that baseverie's gone on the continent. if baseverie's the cute customer that he seems to be, he'd put two and two together when major penteney warned him off riversreade court. he'd probably suspect penteney of setting a watch on him; he may have spotted the very man who was watching. then, if he'd any sense, he'd lead that man a bit of a dance, and eventually double on him. no!—i should say baseverie's back here in town! that's about it, mr. hetherwick. but what's this? here's one of my men coming to meet us. i left word where i should be found."

hetherwick looked up and saw a man, who was obviously a policeman in plain clothes, coming towards them. he was a quiet-looking, stodgy-faced man, but he had news written all over his plain face.

"well, marler?" inquired matherfield as they met. "got something?"

there was nobody about in that quiet corner of lincoln's inn fields, yet the man looked round as if anxious to escape observation, and he spoke in a whisper.

"i believe i've got that chemist!" he answered. "leastways, it's like this. there's a chemist i tried this morning—name of macpherson, in maiden lane. i showed him the facsimiles of the lost labels on the medicine bottles, and asked him if he could give me any information. he's a very cautious sort of man, i think; he examined the facsimiles a long time, saying nothing. then he said he supposed i was a policeman, and so on, and of course i had to tell him a bit—only a bit. then he said, all of a sudden, 'look here, my friend,' he said, 'you'd better tell me, straight out—has this to do with that hannaford poisoning case?' so, of course, i said that, between ourselves, it had. 'isn't matherfield in charge of that?' he said. of course, i said you were. 'very well' he said. 'you send matherfield to me. i'm not going to say anything to you,' he said. 'what i've got to say i'll say to matherfield.' so i went back to head-quarters, and they told me you'd gone to lincoln's inn fields."

"all right, my lad!" said matherfield. "if you've found the right man, i'll remember you. what's his name—macpherson, maiden lane? very good—then i'll just step along and see him. not a word to anybody, marler!" he added, as the man turned away. "keep close. now, this is a bit of all right, mr. hetherwick!" he continued, chuckling and rubbing his hands. "this beats all we heard at penteney's! only let me get the name and address of the man for whom that bottle of medicine was made up, and i think i shall have taken a long stride! but come along—we'll see the chemist together."

the shop in maiden lane before which they presently paused was a small, narrow-fronted, old-fashioned establishment, with little in its windows beyond the usual coloured bottles and over the front no more than the name "macpherson" in faded gilt letters on a time-stained signboard. it was dark and stuffy within the shop, and hetherwick had to strain his eyes to see a tall, thin, elderly, spectacled man, very precise and trim in appearance, who stood behind the single counter, silently regarding him and matherfield.

"mr. macpherson?" inquired matherfield. "just so! good morning, sir. my name is matherfield—inspector matherfield. one of my men tells me——"

"one moment!" interrupted the chemist. he stepped behind a screen at the rear of his shop and presently returned with a young man, to whom he whispered a word or two. then he beckoned to his two visitors, and opening a door at the further corner, ushered them into a private parlour. "we shall be to ourselves here, mr. matherfield," he said. "and i've no doubt your business is of a highly confidential nature."

"something of that sort, mr. macpherson," assented matherfield, as he and hetherwick took chairs at a centre table. "but my man'll have prepared you a bit, no doubt. he tells me he showed you the photographed facsimiles of certain torn labels that are on a medicine bottle which figures in the hannaford case, and that in consequence of your seeing them you asked to see me. well, sir, here i am!"

"aye, just so, mr. matherfield, just so, precisely," replied the chemist, turning up the gas-jet which hung above the table. "aye, to be sure!" he, too, sat down at the table, and folded his thin long fingers together. "aye, and you'll be thinking, mr. matherfield, that yon bottle has something to do with the poisoning of hannaford?"

"i'll be candid with you, mr. macpherson," answered matherfield. "but first let me ask you something. have you read the newspaper accounts of this affair?"

"i've done that, mr. matherfield—yes, all i could lay hands on."

"then you'll be aware that there was another man poisoned as well as hannaford—a man named granett, who was in hannaford's company on the night when it all happened? this gentleman here is the one that was in the underground train and saw hannaford die, and granett make off, as he said, to fetch a doctor."

"that'll be mr. hetherwick, i'm thinking," said the chemist, with a polite bow. "aye, just so!"

"i see you've read the reports of the inquest," remarked matherfield, with a smile. "very well, as i say, granett was found dead later. i discovered a medicine bottle and a glass at his bedside. there'd been whisky in both, but according to the medical experts there had also been poison—the traces, they say, were indisputable. now, on that medicine bottle were two torn labels—on the upper one, as you see from the facsimile photograph, there's been a name written—all that's left is the initial c. and the first letter of a surname, a. all the rest's gone. and what i want to know is—are you the chemist that made up the medicine or the tonic, or whatever it was, that was in that bottle, and, if so, who is the customer for whom you made it, and whose christian name begins with c. and surname with a.? do you comprehend me?"

"aye, aye, mr. matherfield!" answered the chemist eagerly. "i'm appreciating every word you're saying, and very lucid it all is. and i'm willing to give you all the information in my power, but first i'd just like to have a bit myself on a highly pertinent matter. now, you'll be aware, mr. matherfield, if you've seen the newspapers of this last day or two, that there's a firm of solicitors in lincoln's inn fields that's offering a reward of five thousand pounds——"

"i'm well enough aware of it, mr. macpherson," interrupted matherfield with a laugh and a sly glance at hetherwick. "mr. hetherwick and myself have just come straight from their office, and what you want to know is—if you give me information will it be the same thing as giving it to them? you want to make sure about the reward?"

"precisely, mr. matherfield, precisely!" assented the chemist eagerly. "you've hit my meaning exactly. for, of course, when there's a reward like yon——"

"if you give us information, mr. macpherson, that'll lead to the arrest and conviction of the guilty party, you can rest assured you'll get that reward," said matherfield. "and mr. hetherwick'll support me in that, i'm sure."

"i'm satisfied—i'm satisfied, gentlemen!" exclaimed macpherson, as hetherwick murmured his confirmation. "well, it's a strange, black business, and i'd no idea that i would come to be associated with it until that man of yours called in this morning, mr. matherfield. but then i knew! and i'll shorten matters by telling you, at once—i made up the tonic that was in that bottle!"

matherfield rubbed his hands.

"good!" he said quietly. "good! and now, then—the critical question! for whom?"

"for a dr. charles ambrose, from a prescription of his own," replied macpherson. "it's a sort of pick-me-up tonic. i first made it up for him two years ago; i've made it up for him several times since. the last occasion was about six weeks ago. i have all the dates, though, in my books; i can show you them."

"wait a bit," said matherfield. "that's of no great importance—yet. dr. charles ambrose, eh? have you his address?"

"aye, to be sure!" answered the chemist. "his address is 38, number 59, john street."

"adelphi!" suggested matherfield.

"adelphi, precisely—38, number 59, john street, adelphi," repeated macpherson. "that's in the books, too."

matherfield suddenly became silent, staring at the floor. when he looked up again it was at hetherwick.

"didn't granett exclaim that he knew of a doctor, close by, when he rushed out of that train at charing cross underground?" he asked. "gave the impression that he knew of one close by, anyway?"

"he said distinctly close by," answered hetherwick. "why, are you thinking——"

matherfield interrupted him with a wave of the hand, and turned again to the chemist. "you've seen this dr. charles ambrose?" he asked abruptly.

"oh, i have, mr. matherfield, many a time and often," replied macpherson. "but now i come to think of it, not lately."

"when—last?" demanded matherfield.

"i should think last when he called in and told me to make him another bottle of his tonic," answered macpherson, after some thought. "as i said just now, perhaps about six weeks ago. but the books——"

"never mind the books yet. what's this dr. charles ambrose like?"

"a tall, handsome man, distinguished-looking—i should say about forty years of age. a dark man—hair, eyes, beard. he wears his moustache and beard in—well, a sort of foreign fashion; in fact, he's more like a spaniard than an englishman."

"but—is he an englishman?"

"he was always taken by me for an englishman; he speaks like one—that is, like an englishman of the upper classes. he once told me he was an oxford man—we'd been talking about universities."

"well-dressed man?"

"aye, he was that! a smart, fine man."

"did you ever see him in a big, dark overcoat, with a large white silk muffler about his neck and the lower part of his face?"

"aye, i've seen him like that! on chilly evenings. indeed, that's another thing he told me—he was subject to bronchial attacks."

"muffled himself well up, eh?" suggested matherfield.

"aye, just so! he's been in here like that."

matherfield turned to hetherwick with a significant glance.

"that's the man who met hannaford at victoria station that night!—the man that ledbitter saw, and that nobody's seen since!" he exclaimed. "a million to one on it! now then, who is he?"

"you know his name and his address," remarked hetherwick.

"yes—and i know, too, that mr. macpherson here hasn't seen him lately!" retorted matherfield dryly. "how often, now, mr. macpherson, did you use to see him? i mean, did you use to see him at other times than when he came into your shop?"

"oh, yes! i've seen him in the street, outside," replied the chemist. "i've seen him, too, going in and out of rule's, and in and out of romano's."

"in other words," remarked matherfield, "he was pretty well known about this end of the strand. i'm not sure, now, that i don't remember such a man myself—black, silky, carefully-trimmed beard, always a big swell. but—mr. macpherson hasn't seen him lately! hm! do you know if he was in practice, mr. macpherson?"

"i could not say as to that, mr. matherfield. seeing that he called himself dr. ambrose, i supposed he was a medical practitioner, but i don't know what his degrees or qualifications were at all."

matherfield glanced at a row of books which stood over a desk at the side of the parlour.

"have you got an up-to-date medical directory?" he asked. "good! let's look the man up. you turn up his name, mr. hetherwick," he went on as the chemist handed down a volume; "you're more used to books than i am. find out if there's anything about him."

hetherwick turned over the pages of the directory, and presently shook his head.

"there's no charles ambrose here," he said. "look for yourselves."

matherfield glanced at the place indicated and said nothing. macpherson made an exclamation of surprise.

"aye, well, he may be a foreigner, after all," he observed. "but i shouldn't have considered him one, and he certainly told me he was an oxford graduate."

"foreigner or oxforder, i'm going to know more about him!" declared matherfield, rising and grasping his stick with an air of determination. "well, mr. macpherson, we're obliged to you, and if this results in anything—you know! but for the moment—a bit of that caution that you scotsmen are famous for—eh?"

outside, matherfield laid his hand on hetherwick's elbow.

"mr. hetherwick," he said solemnly, "we're on the track—at last! sure as my name's matherfield, we've hit the trail! now we're going to john street, adelphi—and i'll lay you anything you like that the man's vanished!"