I created a big slideshow in iPhoto. I made a huge mistake when I edited one of the images in that slideshow in Aperture. Prior to making that edit in Aperture, a warning popped up saying that if I edited my slideshow in Aperture, I would no longer be able to edit it in iPhoto. I did not realize the huge impact it would have on my slideshow. For reasons too long to list here, I am desperate to be able to edit that slideshow within iPhoto again. Is there any way to reverse what I did? (In case it is relevant, I am on a MacBook Air OS X 10.10 - Yosemite). I welcome any and all responses to my problem. Thank you.