My character is traumatized with guilt for not running out to save a young child from a creature. He himself was actually powerless to help because he would end up dead himself, so he froze watching it happen behind a tree. And so through out the book, he's going to experience flashbacks that plague him in fragments. Basically he starts to experience a fragment of the memory, fades back to reality showing physical ailments of his reaction, another fragment, back to reality again where he struggles to hold on to himself, back once more, and then a climax reaction.