Itachi was already deep in thought over it, but there had been no clue along his way as to what could be doing this, or why. There was obviously something about those who had arrived here by force, rather than nature if the changes were anything to go by...

Frowning, he spent some time studying Sasuke quietly, aware of the tension in his tone. There were some things they could hide from one another, but Itachi knew fear in Sasuke, no matter how small the slice of it.

"When did the pain start?"