These pathological details were established on the arrival later of Mr Bigg, the surgeon, fetched from the Rainbow Coffee-house near by by Fairlow, one of the Temple porters. But the four women could see enough for themselves, without the help of Mr Bigg, to understand how death had been dealt in all three cases. They could see quite clearly also for what motive the crime had been committed. A black strong-box, with papers scattered about it, lay beside Mrs Duncomb's bed, its lid forced open. It was in this box that the old lady had been accustomed to keep her money. If any witness had been needed to say what the black box had contained there was Mrs Rhymer, executrix under the old lady's will. And if Mrs. Rhymer had been at any need to refresh her memory regarding the contents opportunity had been given her no farther back than the afternoon of the previous Thursday. On that day she had called upon Mrs Duncomb to take tea and to talk affairs. Three or four years before, with her rapidly increasing frailness, the old lady's memory had begun to fail. Mrs Rhymer acted for her as a sort of unofficial curator bonis, receiving her money and depositing it in the black box, of which she kept the key. On the Thursday, old Betty and young Nanny being sent from the room, the old lady had told Mrs Rhymer that she needed some money--a guinea. Mrs Rhymer had gone through the solemn process of opening the black box, and, one must suppose--old ladies nearing their end being what they are--had been at need to tell over the contents of the box for the hundredth time, just to reassure Mrs Duncomb that she thoroughly understood the duties she had agreed to undertake as executrix At the top of the box was a silver tankard. It had belonged to Mrs Duncomb's husband. In the tankard was a hundred pounds. Beside the tankard lay a bag containing guinea pieces to the number of twenty or so. This was the bag that Mrs Rhymer had carried over to the old lady's chair by the fire, in order to take from it the needed guinea.