April 24th excerpt:

Sam looked back to find that the tiny kid he’d discovered running for hiding, and his hunting instincts kicked into high gear.

The kid might look small, and might be harmless, but as John Winchester had told Sam a thousand times, might meant nothing if someone got killed over it. If Sam couldn’t find out for sure this kid was harmless, he needed to treat him as a possible threat. And that meant he couldn’t let him vanish into hiding and possibly lose track of him.