see not that long before , this guy had been riding the bus home with his nose pressed against the cold window , minding his own business etc , just like he was then , when a particularly nasty idea popped into his head from god-knows-where but it didnt involve a power plant but rather an elderly nun sitting two seats in front of him ( a squat , motionless woman , with one spindly hand dangling from the black sleeve of her nuns get up , limp and exposed in the aisle ) .