You were in the cave used by Bruce's and Thomas's father.. You found a recording among a table Thomas was working on. You pressed play but the content was puzzling and disturbing. "Dopplegangers.. Someone out in the world or another one looking just like me... No relation, no blood shared. A whole different life but the exact same face and build... He could have an accent, a gang of friends. He could be inferior,weaker or smarter. If I found him I could take his life, his place or worse.. Of course I would need to watch him for a while to truly be ready for any of that. But the people who know him, what could be more of a nightmare than a stranger with the face of a friend?To be hurt by someone that looks familiar, no one would trust him again. "

When you finished you noticed Thomas in the lab. He defended every word he said saying it was just a theory, a motive that couldn't be proven. Saying it was just hypothetical at this point...  But you would doubt his answer.