Sister   When my sister slipped away her slippers fell downstairs slapping the sleeping dog’s nose. She patted him back to rest before silence sealed her closing of the sliding door behind her and I, in my nightgown, slept through it all, unstirred. So how could I know?   I am a slip of my sister. I learned to read by following her finger. I followed the back of her knees when the furious sun flamed the road that summer. She is faster than me, but I am slower. Her school-dress blows in the ash of the dead-dark noon. She…