In 1905 Mr. Cuming Walters published his _Clues to Dickens’s Mystery of Edwin Drood_. The _Athenæum_ expressed its conviction ‘that in these hundred pages or so he has found the clue, the main secret which had baffled all previous investigators, and so has secured permanent association with one of the immortals.’ Mr. Cuming Walters’s book was immediately followed by Mr. Andrew Lang’s _The Puzzle of Dickens’s Last Plot_. In this Mr. Lang adopted with modifications the theory of Mr. Proctor. The subject continued to interest this lamented author to the end of his life. He wrote many letters and articles on the theme, coming ultimately to the conclusion that Dickens did not know himself how his story was to be ended. In 1910 Professor Henry Jackson of Cambridge published a volume, _About Edwin Drood_. It is a work of sterling merit, and particularly valuable for its study of the chronology of the story. Dr. Jackson was the first to examine the manuscript in a scholarly way, and to give some of the chief results. His conclusions are in the main those of Mr. Cuming Walters, but they are supported by fresh arguments and criticisms. There have been many articles on the subject, particularly in that excellent periodical, the _Dickensian_, edited by Mr. B. W. Matz. Of this magazine it may be said that every number adds something to our knowledge of the great author. By far the most successful attempt to finish the book is that of Gillan Vase, which was published in 1878. It is the only continuation worth looking at. Among the best of the periodical contributions are those by Dr. M. R. James of Cambridge, published in the _Academy_, and in the _Cambridge Review_. The papers of Mr. G. F. Gadd in the _Dickensian_ deserve special praise. In the _Bookman_ Mr. B. W. Matz, whose knowledge of Dickens is unsurpassed, has declared for the view that Edwin Drood was murdered, but has not committed himself to any theory of Datchery. I should not have been justified in publishing this volume if I had been able to add no new material. But I venture to think it will be found that while I have freely used the arguments and the discoveries of previous investigators, I have made a considerable addition to the stores. In particular, I have brought out the fact that Forster declined to accept Dickens’s erasures in the later proofs, and I have printed the passages which Dickens meant to have omitted. The effect of the omissions is also traced to a certain extent, though not fully. The more one studies them, the more significant they appear.