He held his breath as the dark shape of the intruder approached and passed him, though he could see little more than an outline. Taller than he was as people generally were, slimmer- and, unless he was mistaken, unarmed, but carrying one of the packs of supplies he'd lost out on earlier. He made the decision.

Quickly, he jumped on the stranger from behind, wrapping his arm around his throat and doing his best to subdue any struggling- hoping a flash of reflected light from the knife in his hand might do the trick.
"Listen," he hissed. "I really, really don't want to kill you, or anybody, actually. But I'd rather not get myself killed either. So. If you leave me your pack, I'll let you go. Alright?"