hetherwick realised at once that mapperley had news, and was waiting there to communicate it. but he looked not so much at mapperley as at mapperley's companion. mapperley, as hetherwick had remarked to more than one person in the course of those proceedings, concealed his sharpness under an unusually commonplace exterior; he looked, as a rule, like a young man whose ideas rarely soared above a low level. but the jew was of a different aspect—hetherwick was not quite sure whether he was rat or ferret. there was subtlety and craft written all over him, from his bright beady eyes to his long, thin, dirty fingers, and before mapperley spoke his employer felt sure that in this son of israel the clerk had found a valuable associate.

"hullo, mapperley!" exclaimed hetherwick. "waiting for me? you've some news, i suppose?"

mapperley, grave and formal, pointed a finger at the jew.

"mr. isidore goldmark, sir," he said. "friend of mine. i got him to give me a bit of assistance in this baseverie and vivian affair. the fact is, sir, he knows vivian's—don't you, issy?"

"thome!" replied mr. goldmark, with a grin.

"and he knows baseverie, too," continued mapperley. "by sight, anyhow. so i got him—for a consideration—to watch for baseverie's next appearance on that scene, and then, when he did come, to keep an eye on him—trick him, in fact. and issy's seen him to-night, mr. hetherwick, and followed him. then issy came to me, and i brought him here."

"good!" said hetherwick. "sit down, both of you, and i'll hear about it." he dropped into his own easy chair and again regarding the jew decided that he was probably a creditable witness. "what do you do at vivian's?" he asked. "employed there?"

mr. goldmark glanced at mapperley and smiled knowingly. mapperley nodded.

"all confidential, issy," he said reassuringly. "going no further."

"of course this is all confidential—and secret," remarked hetherwick. "i only want to know the precise connection between vivian's and mr. goldmark."

"it'th a thort of themi-official, mithter," answered the jew. "the fact ith, i do a bit o' commith'on work for vivian'th cuthtomerth, turf you know. tho'—i'm in and out of an evening. thee?"

"i see," said hetherwick. "all right! and you know baseverie?"

"ath well ath i know my own nothe," replied mr. goldmark.

"how long have you known him?"

"thome time."

"do you know what he is?"

"aint an idea, mithter—and noboody elthe that i knowth of! liv'th on hith wit'th, i should thay, if you athk me. wrong 'un!"

"nor where he lives?"

"no, mithter! all i knowth ith that he come'th to vivian'th—now and then."

"and you saw him to-night?"

"i did, mithter—to-night ath ever wath!"

"what time was that?"

"about eight o'clock, mithter—near ath i can fix it."

"well, what happened?"

"thith, mithter. he came in about eight, ath i thay. i wath there, doing a bit o' bithneth with another cuthmur. batheverie, he didn't thtop. he wathn't in the plathe three minuteth, and while he wath in he theemed—to me—to be a bit fidgety—thuthpithious, like. looked round and about—cautiouth. then he went—and i followed him. according to inthructionth from mapperley there."

"where did he go?"

"well, mithter, i'll give you the particularth—in full: when i theth out on a job o' that thort i do it proper. he turned out o' candlethtick pathage into the lane, and he had a drink at a bar there. then he went to trafalgar square tube. i wath clothe behind him when he booked——"

"a moment. does he know you?"

"may jutht know me by thite, mithter, but not enough to exthite any thuthpithion in hith mind if he thaw me there behind him. i never had no truck with him—never thpoke to him."

"well, go on. where did he book to?"

"warwick avenue, mithter. tho did i—of courth. when we got there, i followed him out—at a thafe dithtance. he turned down to the canal, crothed the bridge, and went down to thant mary'th manthion'th. and there he went in."

hetherwick glanced at mapperley. mapperley permitted himself to wink at his employer—respectfully, but knowingly.

"went into st. mary's mansions, eh?" said hetherwick. "walked straight in?"

"straight in, mithter—front entranth. i thee him, from acroth the road, talking to the man in livery—porter or whatever he hith. i could thee through the glath doorth. then i thee both of 'em go up in the lift. tho i waited about a bit, jutht to thee if he'd come out. he did."

"soon?" asked hetherwick.

"he wath inthide about ten minuteth. then he came out. alone. thith time he went in t'other direction. i followed him acroth paddington green to edgware road tube, and there—well, to tell you the truth, mithter, there i lotht him! there wath a lot o' people about, and i made thure he'd be going thouth. but he mutht ha' gone wetht. anyway, i lotht him altogether."

"well—i think you saw enough to be of help," said hetherwick. "now—just keep this to yourself, goldmark." he motioned mapperley into another room, gave him money for his assistant, and waited until the jew had gone, shown out by the clerk. "eleven o'clock!" he remarked, glancing at his watch as mapperley came back. "mapperley! we're going out—to st. mary's mansions. and after we've been there, and made a call, you'd better come back here with me and take a shake-down for the night—i shall want you in the morning, unless i'm mistaken."

it was one of mapperley's chief virtues that he was always ready to go anywhere and do anything, and he at once accompanied hetherwick to the top of middle temple lane, found a taxi-cab within five minutes, and proposed himself to sit up and shakedown that night and the next, if necessary.

"scent's getting hot, i think, sir," he remarked as they drove off, after bidding the driver carry them to paddington green. "things seem to be coming to a head."

"yes—but i don't think you know everything," answered hetherwick. he proceeded to give the clerk an epitomised account of the day's doings as they had related to himself, concluding with matherfield's theory as expressed after leaving the green archer. "you're a smart chap, mapperley," he added. "what do you think?"

"i see matherfield's point," answered mapperley. "i can follow his line. he thinks like this: hannaford, when he came to london, wanted to get rid, advantageously, of that formula of his about a new ink. he got into touch with ambrose, whom, of course, he'd known before at sellithwaite. ambrose introduced him to some men who deal or dabble in chemicals, of whom one, no doubt, is baseverie, and who seem to have a laboratory or something of that sort somewhere in the westminster district. on the night of the murder ambrose met hannaford, by appointment, at victoria, and took him there. probably, hannaford left the sealed packet—opened by that time—with these fellows. probably, too, while there he told them—jokingly, very likely—what he'd discovered, from the picture in the papers, about the identity of mrs. whittingham and madame listorelle. and now comes in—granett!"

hetherwick gave an exclamation that denoted two or three things—surprise, for one.

"ah!" he said. "granett! to be sure! i'd forgotten granett!"

"i hadn't," remarked mapperley with a cynical laugh. "granett—and his murder—is an essential factor. what i think is this: we know that hannaford met ambrose at victoria station that all-important evening. ambrose, without doubt, took him to the place i hinted at just now—the exact location of which is a mystery. i think hannaford stopped there until late in the evening. but—i also think he went back again! with—granett!"

"ah!" exclaimed hetherwick. "i see!"

"we know," continued mapperley, "that granett went that evening to see the chemist who gave information about him; we know, too, that he and the chemist went and had a drink together, and parted at about closing time, granett then, according to the chemist, going towards victoria street. now i think that granett then met hannaford—accidentally. they'd known each other in sellithwaite. they talked—granett told hannaford he was down on his luck. hannaford, evidently, was a kind-hearted man, and i think he did two things out of kindness for granett. he gave him that five-pound note——"

"that was got at vivian's!" interrupted hetherwick quickly.

"to be sure!" assented mapperley. "but we know that hannaford had been at vivian's—with baseverie—undoubtedly. taken there by baseverie, which makes me certain that for two or three days before his death he'd been in touch with both baseverie and ambrose. hannaford got that fiver in change at vivian's. and he gave it to granett, on hearing his story. but he did something else—something that was far more important—that is far more important—to us!"

"what?" asked hetherwick.

"he turned back to the place he'd just left, and took granett with him!" answered mapperley with confidence. "he knew granett was a trained and qualified chemist; he thought he could get him a job with these men who, presumably, were going to take up his own invention. it would be little more than half-past ten then. where else than at this place are hannaford and granett likely to have been between that time and the time at which they got into your carriage at st. james's park? of course they were there—with ambrose and baseverie."

"as you put it—highly probable," said hetherwick. "two and a half hours—doing what?"

"ah, now we come to the real thing!" exclaimed mapperley. "my own belief is that hannaford was fatally poisoned when he left those two men the first time! they'd two objects in poisoning him—or, to put it another way, he'd entrusted them with two secrets—one about madame listorelle; the other about his invention. they wanted to keep both to themselves and to profit by both. the invention, no doubt, has considerable value—hannaford believed it had, anyway. they thought they could blackmail madame and her sister, lady riversreade. so, before hannaford left them the first time, they poisoned him—cleverly, subtly, devilishly—knowing that so many hours would elapse before the poison worked, and that by that time he'd be safe in bed at his hotel and would die in his sleep. but—he went back to them again, and took another man with him! so—that man had to die, too!"

hetherwick thought awhile in silence.

"all very good theory, mapperley," he said at last. "but—it may be nothing but theory. why did granett run off at charing cross?"

"because granett knew that ambrose lived in john street, close by," replied mapperley with promptitude. "he may have known it before; he may not have known it until that evening. but—he knew it! most likely he thought that ambrose had returned home from the place in westminster: ambrose may have left there before hannaford and granett did. anyway, we may be reasonably certain that when granett left you with the dying or dead man, he ran off to ambrose's flat—a few minutes away."

"why didn't he come back?" demanded hetherwick. "i'm only wanting to get at probabilities."

"i've thought of that, too," replied mapperley. "i think he found ambrose out. but by that time he'd had time to reflect. he knew something was wrong. he knew that if he went back, he'd find the police there, and would be questioned. he might be suspected. and so—he went home, with the bottle in which ambrose had given him a drop of whisky for himself. and—died in his sleep, as they thought hannaford would."

"why should ambrose have that bottle down at westminster?" asked hetherwick.

"why shouldn't he?" retorted mapperley. "a man who's taking a tonic takes it at least three times a day—regularly. he'd have his bottle with him. probably there are several similar empty bottles there at that place."

"where is that place?" exclaimed hetherwick. "where?"

"got to be found," said mapperley, as the cab came to a stand. "but—here's this!"

hetherwick led his companion across paddington green and to the house from which he and matherfield had watched the flats opposite. late as it was, the lodging-house keeper was up, and lent a willing ear to hetherwick's request that he should go with him to his friend the caretaker of the mansions. that functionary was at supper. he continued to sup as hetherwick, morally supported by the lodging-house man, explained matters to him, but at last he allowed his cheek to bulge with unswallowed food and turned a surprised and knowing eye on his principal visitor.

"blamed if i didn't wonder whether it was all o.k. with that chap!" he exclaimed, banging the table with the haft of his knife. "for all he was quite the gentleman, i somehow suspicioned him! and yet, he'd a straight tale to tell: come here on madame's behalf, to get something for her out of her rooms, had her keys, and give me a note from her saying as how i was to allow the bearer to go up to her flat! what more could i expect—and what could i do—under the circs? i asks yer!"

"oh, he had a note, had he?" inquired hetherwick. "in madame's writing?"

the caretaker laid down his knife, and thrusting his hand in his breast-pocket, drew forth an envelope and silently handed it over. it was an azure-tinted envelope, of a very good quality of paper, such as is only sold in high-class stationery shops, and the sheet inside matched it in tint and quality. but hetherwick at once noticed something about that sheet; so, too, did mapperley, peering at it from behind his elbow. about an inch and a half had been rather roughly cut off at the top; obviously some address had been engraved, or embossed, or printed on the missing portion. as for what was written on the sheet, it was little—a simple order that the caretaker should allow bearer to go into madame listorelle's flat.

"you recognised that as madame's handwriting?" suggested hetherwick.

"oh, that's her fist, right enough, that is!" replied the caretaker. "i knew it at once. and no wonder! i ain't no scholard, not me!—but i knows enough to know that it 'ud puzzle one o' them here forgers as ye reads about to imitate that there sort o' writing—more like as if it had been done with a wooden skewer than a christian pen! oh, that's hers."

hetherwick handed the letter and envelope to mapperley, who was holding out a hand.

"well," he said. "i wish ye'd just let me have a look into madame's flat. there's something seriously wrong, and——"

"oh, you can do that—'long as i'm with you," said the caretaker readily. he rose and led the way to the left, and presently ushered them into a smart flat and turned on the electric light. "don't see nothing wrong here," he observed. "the chap wasn't here ten minutes, and he carried nothing heavy away, whatever he had in his pockets."

hetherwick and mapperley looked round. everything seemed correct and in order—the surroundings were those of a refined and artistic woman, obviously one who loved order and system. but on a desk that stood in the centre of the sitting-room a drawer had been pulled open, and in front of it lay scattered a few sheets of madame listorelle's private notepaper, with her engraved address and crest. near by lay some envelopes, similarly marked. and with a sudden idea in his mind, hetherwick picked up a sheet or two of the paper and a couple of envelopes and put them in his pocket.

a few minutes later, once more in the cab which they had kept waiting, and on the way to hill street, whither hetherwick had bidden the driver go next, mapperley turned to his employer with a sly laugh, and held up something in the light of a street lamp by which they were passing.

"what's that?" asked hetherwick.

"the order written by madame listorelle," answered mapperley, chuckling. "the caretaker didn't notice that i carried it off, envelope and all, under his very eyes! but i did—and here it is!"

"what do you want to do with it?" demanded hetherwick. "what's your notion?"

but mapperley only chuckled again and without giving any answer restored the azure-tinted envelope and its contents to his pocket.