Lost narration

I'm using Premier elements 15 and I have lost some narration from part of my video. I've been told it will be there somewhere. I have looked all along the timeline and in project assist, but can't find it. My only option is to add this bit of video again and start re-editing it. I really haven't got time to do this. Please can anyone guide me as to where I can find this piece of narration, or is it a hopeless case?

Many thanks