Many thanks, Barb and James for these suggestions, which may well be useful to me in the future. I tried them without success, however, and was just about tearing my hair out, as I thought I was going to have to strip out all the endnotes and reinsert them one by one. Then I discovered that the problem was not Indesign's endnote feature but entirely my own stupid fault. At some point (trying to resize some pictures) I had cut the bit of text containing note 67, then repasted it into a new text box which was independent of the rest of the text in the book. I had forgotten this when I noticed note 67 was missing. So every time I was reinserting the note, Indesign treated it as a note on a separate bit of text unrelated to the rest of the text and notes in the book. The solution was to cut the rogue piece of text again and paste it into the main text of the book and then note 67 could be inserted in its correct order. I am posting this not so as to parade my own incompetence, but in the hope that if anyone else makes the same mistake in the future they will stumble across this solution! Thanks again for your generous help. Tom.