Sigma is surprised to find himself awash with gratitude as the other sets him free. Though the Tribute had been the one to attack him in the first place, he had a hunch the man was only doing what came naturally to parents, a misdirected visceral terror one first had to feel to understand. The Doctor had done the very same and worse to Donatello when he'd found out he'd killed Kyle, after all.

It makes him stop the man before he can leave. "What's your name?" He wants to ask, are you her father? This was a far less harmful substitute.