'But here we come to a curious point: she had the opportunity of substituting the blank paper, but no motive. The will was in her favour, and by substituting a blank piece of paper she despoiled herself of the heritage she had been so anxious to gain. The same applies to Mr. Spragg. He, too, had the opportunity. He was left alone with the document in question for some two or three minutes in my office. But again, it was not to his advantage to do so. So we are faced with the curious problem: the two people who had the opportunity of substituting a blank piece of paper had no motive for doing so, and the two people who had a motive had no opportunity. By the way, I would not exclude the housemaid, Emma Gaunt, from suspicion. She was devoted to her young master and mistress and detested the Spraggs. She would, I feel sure, have been quite equal to attempting the substitution if she had thought of it. But although she actually handled the envelope when she picked it up from the floor and handed it to me, she certainly had no opportunity of tampering with its contents and she could not have substituted another envelope by some sleight of hand (of which anyway she would not be capable) because the envelope in question was brought into the house by me and no one there would be likely to have a duplicate.'
He looked round, beaming on the assembly.
'Now, there is my little problem. I have, I hope, stated it clearly. I should be interested to hear your views.'
To everyone's astonishment Miss Marple gave vent to a long and prolonged chuckle. Something seemed to be amusing her immensely.
'What is the matter, Aunt Jane? Can't we share the joke?' said Raymond.
'Mr. Petherick's story is a catch. So like a lawyer! Ah, my dear old friend!' She shook a reproving head at him.
'I wonder if you really know,' said the lawyer with a twinkle.
Miss Marple wrote a few words on a piece of paper, folded them up and passed them across to him.
Mr. Petherick unfolded the paper, read what was written on it and looked across at her appreciatively.
'My dear friend,' he said, 'is there anything you do not know?'
'I knew that as a child,' said Miss Marple. 'Played with it too. '
' I feel rather out of this, ' said Sir Henry. 'I feel sure that Mr. Petherick has some clever legal legerdemain up his sleeve. '
'Not at all,' said Mr. Petherick. 'Not at all. It is a perfectly fair straightforward proposition. You must not pay any attention to Miss Marple. She has her own way of looking at things.'
The lawyer shook his head.
'I will go on where I left off. I was dumbfounded and quite as much at sea as all of you are. I don't think I should ever have guessed the truth probably not - but I was enlightened. It was cleverly done too.
'I went and dined with Philip Garrod about a month later, and in the course of our after dinner conversation, he mentioned an interesting case that had recently come to his notice.
'I should like to tell you about it, Petherick, in confidence, of course.'
'Quite so,' I replied.
'A friend of mine who had expectations from one of his relatives was greatly distressed to find that that relative had thoughts of benefiting a totally unworthy person. My friend, I am afraid, is a trifle unscrupulous in his methods. There was a maid in the house who was greatly devoted to the interests of what I may call the legitimate party. My friend gave her very simple instructions. He gave her a fountain pen, duly filled. She was to place this in a drawer in the writing-table in her master's room, but not the usual drawer where the pen was generally kept. If her master asked her to witness his signature to any document and asked her to bring him his pen, she was to bring him not the right one, but this one which was an exact duplicate of it. That was all she had to do. He gave her no other information. She was a devoted creature and she carried out his instructions faithfully.'
'He broke off and said, 'I hope I am not boring you, Petherick.'
'Not at all,' I said. 'I am keenly interested.' Our eyes met.
'My friend is, of course, not known to you,' he said.
'Of course not,' I replied.
'Then that is all right,' said Philip Garrod.
'He paused then said smilingly, 'You see the point? The pen was filled with what is commonly known as Evanescent Ink - a solution of starch in water to which a few drops of iodine has been added. This makes a deep blue-black fluid, but the writing disappears entirely in four or five days.'
Miss Marple chuckled.
'Disappearing ink,' she said. 'I know it. Many is the time I have played with it as a child.'
And she beamed round on them all, pausing to shake a finger once more at Mr. Petherick.
'But all the same it's a catch, Mr. Petherick, ' she said. 'Just like a lawyer.'
The Thumb Mark of St Peter
'And now, Aunt Jane, it is up to you,' said Raymond West
'Yes, Aunt Jane, we are expecting something really spicy,' chimed in Joyce Lumpier.
'Now, you are laughing at me, my dears,' said Miss Marple placidly. 'You think that because I have lived in this out-of-the-way spot all my life I am not likely to have had any very interesting experiences.'
'God forbid that I should ever regard village life as peaceful and uneventful,' said Raymond with fervour. 'Not after the horrible revelations we have heard from you! The cosmopolitan world seems a mild and peaceful place compared with St Mary Mead.'
'Well, my dear,' said Miss Marple, 'human nature is much the same everywhere, and, of course, one has opportunities of observing it at close quarters in a village.'
'You really are unique. Aunt Jane,' cried Joyce. 'I hope you don't mind me calling you Aunt Jane?' she added. 'I don't know why I do it.'
'Don't you, my dear?' said Miss Marple.
She looked up for a moment or two with something quizzical in her glance, which made the blood flame to the girl's cheeks. Raymond West fidgeted and cleared his throat in a somewhat embarrassed manner.
Miss Marple looked at them both and smiled again, and bent her attention once more to her knitting.
'It is true, of course, that I have lived what is called a very uneventful life, but I have had a lot of experience in solving different little problems that have arisen. Some of them have been really quite ingenious, but it would be no good telling them to you, because they are about such unimportant things that you would not be interested - just things like: Who cut the meshes of Mrs Jones's string bag? and why Mrs Sims only wore her new fur coat once. Very interesting things, really, to any student of human nature. No, the only experience I can remember that would be of interest to you is the one about my poor niece Mabel's husband.
'It is about ten or fifteen years ago now, and happily it is all over and done with, and everyone has forgotten about it. People's memories are very short - a lucky thing, I always think.'
Miss Marple paused and murmured to herself:
'I must just count this row. The decreasing is a little awkward. One, two, three, four, five, and then three purl; that is right. Now, what was I saying? Oh, yes, about poor Mabel.
'Mabel was my niece. A nice girl, really a very nice girl, but just a trifle what one might call silly. Rather fond of being melodramatic and of saying a great deal more than she meant whenever she was upset She married a Mr Denman when she was twenty-two, and I am afraid it was not a very happy marriage. I had hoped very much that the attachment would not come to anything, for Mr Denman was a man of very violent temper - not the kind of man who would be patient with Mabel's foibles - and I also learned that there was insanity in his family. However, girls were just as obstinate then as they are now, and as they always will be. And Mabel married him.