Created slideshow, now it is gone

Oh, please be someone who can help! I am running iPhoto '11 9.4.3. I spent *hours* creating a slideshow, as I was adding music, it hung - could not even do a force quit. Had to do hard re-boot. Now, folder is still there, but empty. Same with folder on Time Machine. I had a previous version in trash, but that one is empty too.

I have tried file-finder programs, no use.

Please tell me there is a way to recover! Or, if not, I can at least re-do it knowing the old is totally lost.

Thank you for any help / suggestions!