We've left the guided tour. My sons discover a notch on the hillside, a cave closed by swords of brambles. We duck and enter the cool dark, nervous and no matches. Sentries crouched here, spying at enemy ships during the occupation.
Old photos show Japanese soldiers in Nanjing practicing bayonet drills on bound Chinese prisoners.
From our lookout we spy white flags of waves marching in afternoon sun. We emerge, blinking like newborns. Below, tired Chinese tourists straggle back to busses. Here, black butterflies whirl like bits of paper, harmless, their occupation of the hill complete, the small pages of their wings chronicling the history of life and death on earth in a language lighter than air.