Dana
My guess is that when you force quit the application you lost the Book as it was not written to the database file.
Books (like albums, slideshows etc) are
virtual entities. There is no folder on your hard disk with your book or albums, they are entries in the main database file - essentially, they are an instruction to the application: 'Display these pics together'.
Any time that iPhoto is disturbed writing to the db file (like when you did the hard shut down) then there is a risk on the db being corrupted.
So, no, there's nowhere your project is hiding.
The only possibility s that Time Machine may have backed up at
some point while you were working, so it may have a part of it. I don't use TM, so for details on recovering from it check the Help or post on the TM forum.
Do a search for Old Toad. He's the most knowledgeable poster on here and he has generously created a Automator app that will back up the db file while you're working. It's usually attached to his posts as a signature.
Regards
TD