Before you create the PDF from the book, use the Preflight Book command. Even using the default preflight profile, it will let you find and fix overset text in your book.
Put your text cursor in the first story ( the one with the overset) and go to Edit > Edit in Story Editor. Whatever is overset will show up in story editor byond the red demarcation line. If it's repeated content you can slect it and delete (or ignore it -- overset should not be a fatal error for export). If you need it, fix it.
Got to page 135 and right click the text frame. Choose Edit in Story Editor.
It’s pretty self-explanatory once you open it up.
If you’re completely unconcerned about what’s there, insert you cursor at the end of the text and press cmdshiftend/ctrlshiftend. This will select all the text between the insertion point and the end of the story.
Press delete and you’re done.
Thanks Steve, Peter and Bob...all fixed! I had nightmares after all the work that went into this that the outcome might be disastrous. But. thanks to you, all is well. Much Appreciated!