" Mrs Cavendish, therefore, made her plans as only woman driven desperate through jealousy done evening she unbolted the door leading into Mademoiselle Cynthia's room Possibly she applied oil hinges, for opened quite noiselessly when I tried it She put off her project until the early hours morning as being safer, servants were accustomed to hearing her move about her room She dressed completely in her land kit, and made her way quietly through Mademoiselle Cynthia's room into that of Mrs Inglethorp ''

He paused moment, and Cynthia interrupted:

"But woken up if anyone had come through my room ? ''

"Not were drugged, mademoiselle ''

"Drugged ? ''

"Mais, oui ! ''

"You remember'' -- he addressed us collectively again -- "that through all the tumult and noise next door Mademoiselle Cynthia slept That admitted of two possibilities Either her sleep was feigned -- which believe -- or her unconsciousness was indeed by artificial means

" latter idea in my mind, I examined all the coffee-cups most carefully, remembering Mrs Cavendish who had brought Mademoiselle Cynthia her coffee the night before sample from each cup, and had them analysed -- with no result I had counted the cups carefully, event of one having been removed Six persons had taken coffee, and six cups were duly found I had to confess myself mistaken

"Then I discovered that I guilty of very grave oversight Coffee brought in for seven persons, not six, for Dr Bauerstein there that evening This changed the face whole affair, for now one cup missing The servants noticed nothing, since Annie, the housemaid, who took coffee, brought in seven cups, not knowing that Mr Inglethorp never drank it, whereas Dorcas, who cleared them away the following morning, found six as usual -- or strictly speaking she found five, the sixth being the one found broken in Mrs Inglethorp's room

" confident missing cup of Mademoiselle Cynthia I had an additional reason belief fact that all the cups found contained sugar, which Mademoiselle Cynthia never took in her coffee My attention was attracted story of Annie about some 'salt' tray of coco which she took every night to Mrs Inglethorp's room I accordingly secured sample coco, and sent it analysed ''

"But that had already been done by Dr Bauerstein,'' said Lawrence quickly

"Not exactly The analyst was asked by him to report whether strychnine was, or was not, present have it tested, as , for narcotic ''

"For narcotic ? ''

"Yes analyst's report Mrs Cavendish administered safe, but effectual, narcotic to both Mrs Inglethorp and Mademoiselle Cynthia And possible that she had mauvais quart d'heure in consequence ! Imagine her feelings when her mother-in-law is suddenly taken ill and dies, and immediately after she hears the word 'Poison' ! She has believed sleeping draught she administered was perfectly harmless, but that terrible moment she feared that Mrs Inglethorp's death lay at her door seized with panic, and under its influence she hurries downstairs, and quickly drops the coffee-cup and saucer used by Mademoiselle Cynthia into large brass vase, where discovered later by Monsieur Lawrence The remains coco she dare not touch Too many eyes are upon her Guess at her relief when strychnine is mentioned, and she discovers that after all the tragedy her doing

" now able to account symptoms of strychnine poisoning being in making their appearance narcotic taken with strychnine will delay the action poison for some hours ''

Poirot paused Mary looked up at him, the colour slowly rising in her face

"All said is quite true, Monsieur Poirot It most awful hour life never forget it But wonderful I understand now -- -- ''

"What I meant when you that safely confess to Papa Poirot, eh ? But trust me ''

" everything now,'' said Lawrence "The drugged coco, taken on top poisoned coffee, amply accounts delay ''

"Exactly But coffee poisoned, or not ? We come to little difficulty here, since Mrs Inglethorp never drank it ''

"What ? '' The cry of surprise was universal

"No remember my speaking of stain carpet in Mrs Inglethorp's room ? There were some peculiar points stain still damp, it exhaled strong odour of coffee, and imbedded nap carpet some little splinters of china What had happened was plain , for not two minutes before I had placed my little case table near the window, table, tilting up, had deposited it floor on precisely the identical spot In exactly the same way, Mrs Inglethorp had laid down her cup of coffee on reaching her room the night before, treacherous table had played her the same trick

"What happened next is mere guess work on my part, but say that Mrs Inglethorp picked up the broken cup and placed it table bed Feeling in need of stimulant of some kind, she heated up her coco, and drank it off then and there Now faced with new problem the coco contained no strychnine The coffee was never drunk Yet the strychnine must administered between seven and nine o'clock that evening What third medium was there -- medium so suitable for disguising the taste of strychnine extraordinary no one has thought of it ? '' Poirot looked round the room, and then answered himself impressively "Her medicine ! ''

" murderer introduced the strychnine into her tonic ? '' I cried

" no need to introduce it already there -- mixture The strychnine that killed Mrs Inglethorp identical strychnine prescribed by Dr Wilkins that clear , read you an extract from book on dispensing which Dispensary Red Cross Hospital at Tadminster:

" 'The following prescription has become famous in text books:

Strychninae Sulph . . . gr I

Potass Bromide . . . 3vi

Aqua ad . . . . . 3viii

Fiat Mistura

This solution deposits in few hours the greater part strychnine salt as an insoluble bromide in transparent crystals lady in England lost her life by taking similar mixture: the precipitated strychnine collected bottom, and in taking the last dose she swallowed nearly all of it ! ''

"Now , , no bromide in Dr Wilkins' prescription, but remember that I mentioned an empty box of bromide powders powders introduced full bottle of medicine would effectually precipitate the strychnine, book describes, and cause it taken last dose learn later person who usually poured out Mrs Inglethorp's medicine was always extremely careful not to shake the bottle, but to leave the sediment bottom of it undisturbed

" case, been evidences tragedy was intended place on Monday evening , Mrs Inglethorp's bell wire was neatly cut, and on Monday evening Mademoiselle Cynthia was spending the night with friends, Mrs Inglethorp quite alone right wing, completely shut off from help of any kind, and died, in all probability, before medical aid summoned But in her hurry village entertainment Mrs Inglethorp forgot her medicine, she lunched away from home, so last -- and fatal -- dose was actually taken twenty-four hours later than anticipated murderer; and owing delay final proof -- the last link chain -- is now in my hands ''

Amid breathless excitement, he held out three thin strips of paper

"A letter murderer's own hand-writing, mes amis ! Had it been little clearer in its terms, possible that Mrs Inglethorp, warned , escaped As , she realized her danger, but not the manner of it ''

deathly silence, Poirot pieced together the slips of paper and, clearing his throat, read:

" 'Dearest Evelyn:

' anxious at hearing nothing all right -- only to-night instead of last night You understand There's coming once the old woman is dead and way No one can possibly bring home the crime That idea of yours bromides was stroke of genius ! But very circumspect false step -- -- '

"Here, my friends, the letter breaks off Doubtless the writer was interrupted; but there no question as identity We all know this hand-writing and -- -- ''

howl that was almost scream broke the silence

"You devil ! How did you get it ? ''

chair was overturned Poirot skipped nimbly aside quick movement part, assailant fell with crash