Guy rummages through the rustling plastic bags and trash with which he's filled his backpack until finally, at the peak of his frenzy, he announces, "Shit!" loudly enough for the entire train to turn his direction, then punches the bench next to him hard, making a resounding crack.
He catches a woman a few seats down watching him and this enrages him for some reason. "What?" he demands, ready for an attack, an argument, a fight, hoping for someone upon whom to vent his rage.
She shakes her head then looks away, and he contents himself with muttering "Shit," over and over under his breath in a disappointed voice.