"It was Gudge--Mrs.Gudge, the sister-in-law of--" Here Miss Gibson made an unceremonious dive into the open bag and fished out a tiny parcel wrapped in notepaper and secured with a silk thread.
"Thank you," said Thorndyke, taking it from her hand just as Mrs.Hornby was reaching out to intercept it.

He cut the thread and drew from its wrappings a little book bound in red cloth, with the word "Thumbograph" stamped upon the cover, and was beginning to inspect it when Mrs.Hornby rose and stood beside him.
"That," said she, as she opened the book at the first page, "is the thumb-mark of a Miss Colley.

She is no connection of ours.

You see it is a little smeared--she said Reuben jogged her elbow, but I don't think he did; at any rate he assured me he did not, and, you know--" "Ah! Here is one we are looking for," interrupted Thorndyke, who had been turning the leaves of the book regardless of Mrs.Hornby's rambling comments; "a very good impression, too, considering the rather rough method of producing it." He reached out for the reading lens that hung from its nail above the mantelpiece, and I could tell by the eagerness with which he peered through it at the thumb-print that he was looking for something.

A moment later I felt sure that he had found that something which he had sought, for, though he replaced the lens upon its nail with a quiet and composed air and made no remark, there was a sparkle of the eye and a scarcely perceptible flush of suppressed excitement and triumph which I had begun to recognise beneath the impassive mask that he presented to the world.
"I shall ask you to leave this little book with me, Mrs.Hornby," he said, breaking in upon that lady's inconsequent babblings, "and, as I may possibly put it in evidence, it would be a wise precaution for you and Miss Gibson to sign your names--as small as possible--on the page which bears Mr.Reuben's thumb-mark.