"I wonder if it would create a paradox if I killed him?" Marcus asked no one in particular, while his younger self flailed in his arms.
Meanwhile, a tousled blonde head peered around the corner and giggled, waving a toy train before running off. The younger Marcus flailed and screamed more, and the older one set him down.
As fast as he'd come in, he left, chasing his sister. Several minutes later there was a more adult voice, also loud, from the next room, and then silence.