removed； placed in another casket and buried。 There is a square opening or peep hole on the top of the casket through which you can look at the body； a cleverly concealed door covers this opening。 In fact；〃 added McIntyre； 〃the door at the end is not at first discernible； and is hard to open； unless one has the knack of doing so。〃
〃Hum！ It looks as if whoever put Grimes inside the casket was familiar with it；〃 remarked Ferguson dryly； and McIntyre bit his lip。 〃Guess I'll go and take a look at the casket。 I'll come back； Grimes。〃
Kent rose with the others and started to follow them to the door； but Grimes beckoned him to approach the bed。 The butler waited until he heard McIntyre's heavy tread and the lighter footfall of the detective recede down the hall before speaking。
〃I was only going to say； sir；〃 he whispered as Kent； at a sign from him； stooped over the bed； 〃I got a box of aconitine pills for Mrs。 Brewster on Sunday … the stuff that poisoned Mr。 Turnbull；〃 he paused to explain。
〃Yes； go on；〃 urged Kent； catching the man's excitement。 〃You gave it to Mrs。 Brewster …〃
〃No； sir； I didn't； I left the box on the hall table；〃 Grimes cleared his throat nervously。 〃I dunno who picked up that box o' poison； Mr。 Kent； so help me God； I dunno！〃
Kent thought rapidly。 〃Have you told any one of this？〃 he asked。
Grimes nodded。 〃Only one person；〃 he admitted。〃 I spoke to Miss Barbara last night as she was going to bed。〃 Grimes laid a hot hand on Kent's and glanced fearfully around the room。 〃Bend nearer； sir； I don't want none other to hear me。 Just before I got that knockout blow in the library last night； I heard the swish o' skirts … and Miss Barbara was the only living person who knew I knew about the poison。〃
Kent stared in stupefaction at the butler。 He was aroused by a cold voice from the doorway。
〃We are waiting for you； Kent；〃 and Colonel McIntyre stood aside to let him pass from the room ahead of him； then without a backward glance at the injured butler； he closed and locked the bedroom door。
CHAPTER XVIII
THE FATAL PERIOD
As Kent walked into the library he found Colonel McIntyre by his side； the latter's even breathing gave no indication of the haste he had made down the staircase to catch up with Kent。
Detective Ferguson hardly noted their arrival； his attention being given wholly to the examination of the Venetian casket which had played such an important part in the drama of the night before。 The casket and its companion piece stood on either side of the room near a window recess。 The long straight shape of the high boxes on their graceful base gave no indication of the use to which they had been put in ancient days； but made attractive as well as unique pieces of furniture。
Kent crossed the library and； after looking inside the casket； examined the exterior with care。
〃Don't touch that crest；〃 cautioned Ferguson； observing that Kent's glance remained focused on the blood…stained； raised letter 〃B〃 and the carving back of it。 〃In fact； don't touch any part of the casket； I'm trying to get finger prints。〃
Kent barely heard the warning as he turned to McIntyre。
〃Haven't I seen that letter 'B' design on your stationery； Colonel？〃 he asked。
〃Barbara uses it；〃 was the reply。 〃She fancied the antique lettering； and copied the 'B' for the engraver； she is handy with her pen； you know。〃
〃Did she wish the 'B' for a seal？〃 inquired Kent。
〃Yes； she had a seal made like it also。〃 McIntyre moved closer to the casket。 〃Found anything； Ferguson？〃
The detective withdrew his head from the opening at the end of the casket； and regarded the furniture vexedly。
〃Not a thing；〃 he acknowledged。 〃Except I am convinced that it required dexterity to slip Grimes inside the casket。 The butler is small and slight； but he must have been unconscious from that tap on the forehead and； therefore； a dead weight。 Whoever picked him up must have been some athlete； and〃 … running his eyes up and down Colonel McIntyre's well…knit； erect frame … 〃pretty familiar with the workings of this casket。〃
〃Pooh！ It's not so difficult a feat；〃 McIntyre shrugged his shoulders disdainfully。 〃My daughters； as children； used to play hide and seek inside the casket with each new governess。〃
Ferguson stepped forward briskly。 〃Mr。 Kent； let me see if I can lift you inside the casket； make yourself limp … that's it！〃 as Kent； entering into the investigation heart and soul； relaxed his muscles and fell back against the detective。
A moment later he was swung upward and pushed head…first inside the casket and the door closed。 The air； though close； was not unpleasant and Kent； his eyes growing gradually accustomed to the dark interior； tried to discover the trap door at the top of the box but without success。 Putting out his hands he felt along the top。 The height of the casket did not permit him to sit up； so he was obliged to slide his body down toward his feet to feel along the sides of the casket。 This maneuver soon brought his knees in violent contact with the top； and at the sound Ferguson opened the door and assisted him out。
〃Had enough of it？〃 he asked； viewing Kent's reddened cheeks with faint amusement。 〃I wonder if Grimes could breathe in there for any lengthy period。 If so； it would help establish the time which elapsed between his being incarcerated and your finding him； Colonel。〃
〃How so？〃 demanded McIntyre。
〃Well； if he couldn't get air and you hadn't discovered him at once； he'd have died；〃 explained Ferguson。 〃If you did find him immediately the person who knocked him down must have made a lightning escape。〃
〃Air does get in the casket in some way；〃 broke in Kent。 〃It wasn't so bad inside。 Colonel McIntyre；〃 Kent stopped a moment to remove a piece of red sealing wax clinging to the cuff of his suit。 It had not been there when he entered the casket。 Kent dropped the wax in his vest pocket as he again addressed his host。 〃Who first discovered Grimes in the casket？〃
〃Mrs。 Brewster。〃
〃And what was Mrs。 Brewster doing in the library at that hour？〃 glancing keenly at McIntyre as he put the question。
〃She could not sleep and came down for a book；〃 explained the Colonel。
Ferguson； who had walked several times around the library； looking behind first one and then the other of the seven doors； paused to ask：
〃What attracted Mrs。 Brewster's attention to the casket？〃
〃The blood stain on its side；〃 McIntyre answered。
〃What … that！〃 Ferguson eyed McIntyre incredulously。 〃Come； sir； do you mean to tell me she noticed that little bit of a stain in a dark room？〃
〃She had an electric torch；〃 shortly。
〃But why should she turn the torch on this casket？〃 persisted the detective。 〃She came to the library for a book； and the bookcases are in another part of the room。〃
〃Quite so； but the book she wished was lying on the top of this casket；〃 replied McIntyre； meeting their level looks with one equally steadfast。 〃I know because I left the book there。〃
Ferguson glanced from McIntyre to Kent and back again at the Colonel in non…plussed silence。 The explanation was pat。
〃I'd like to talk with Mrs。 Brewster；〃 he remarked dryly。
〃Certainly。〃 McIntyre pressed an electric button。 The summons was answered immediately by the new servant； Murray。 〃Ask Mrs。 Brewster if she can see Detective Ferguson in the library； Murray；〃 McIntyre directed。
〃Beg pardon； sir； but Mrs。 Brewster has just gone out；〃 and with a bow Murray withdrew。
Kent； who had drawn forward a chair preparatory to sitting down and participating in the interview with the widow； changed his mind。
〃I must leave at once；〃 he said； after consulting his watch。 〃Please inform Mrs。 Brewster； Colonel； that I will be in my office this afternoon； and I expect her to make me the visit she postponed this morning。 Ferguson；〃 turning back to address the detective； 〃you'll find me at the Saratoga for the next hour。 Good morning；〃 and paying no attention to Colonel McIntyre's request to remain； he left the room。
There was no one in the hall and Kent debated a moment whether or not to ring for the servant and ask to see Barbara； but； at sight of the hall table； Grimes' confidences recurred to him and drove everything else out of his mind。 Stopping before the table he contemplated its smooth surface before moving the few ornaments it held。 Satisfied that no pillbox stood behind any of them； he pulled open the two drawers and tumbled their contents about。 His efforts only brought to light some half…empty cigarette boxes； matches； a scratch pad or two； and old visiting cards。
Kent shut the drawers； picked up his hat； and took his cane from the tall china umbrella…stand by the hall table。 As he stepped through the front doorway he caught sight of the end of his cane； which he was carrying tucked under his arm。 Fastened to the ferule of the cane was the round top of a paste…board pill box。
Kent backed so swiftly into the house again that his figure blocked the closing of the front door； which he had started to pull shut after him。 Letting the door close gently he walked back to the umbrella stand。 It was a tall heavy affair； and he had some difficulty in tipping it over and letting its contents spill on the floor。 A soft exclamation escaped him as three little pellets rolled past him； and then came the bottom of a box。
With hasty fingers Kent picked them up； placed them in the box； and fitted on the top； first carefully smoothing over the hole made by his cane when thrust into the umbrella stand by the footman。 Replacing the stand he wrapped the box containing the pills in his handkerchief and hurried from the house。
Kent found the operative from Detective Headquarters sitting on duty in Rochester's living room when he entered that apartment a quarter of an hour later。
〃Any one called here？〃 he asked； as the man； whom he had met the night before； greeted him。
〃Not a soul； Mr。 Kent。〃 Nelson suppressed a yawn； his relief was late in coming； and he had had little sleep the night before。 〃There's been no disturbance of any kind； not even a ring at the telephone。〃
Kent considered a moment； then sat down by the telephone and gave a number to Central。
〃That