[ WP ] Write a short story in which an artist makes a frightening discovery while working on an future exhibit . ( More prompt details in text )

IT's the same man, I'm sure of it. 
 
 I started work on this project, *They Died Too Young*, fifteen years ago. I'd ask permission from families who lost children between the ages of 5 and 8. I woudl attend the funerals, and in exchange, I would photograph them in their moment of grief. I would give those families both money and copies of the photos. 
 
 But as time went by, I noticed this... man... in them. Always hanging at the back, he would look exactly the same; around six feet tall, with a stetson hat, and slight greying at his temples. His beard would always be silvered the way through, and he would always have dark glasses and a trenchcoat on. 
 
 This was in fifteen thousand pisctures that were due to be winnowed down to the final thirty for this project. On the last photo, which I had just developed in my dark room, the man had a message for me. 
 
 ^Do not contact me, I will contact you on the pre-opening of your show and tell you everything. 
 ^If you do otherwise, I shall be forced into... unnecessary wastes of energy. 
 
 As clear as day, despite the fact that these were essentially blown up in preparation fro the exhibit. 
 
... Well, *damn*.
