We go up to the second floor, to a room that has a bed on the right and a bunk bed on the left, for the three boys: Raad, Saif a-Din and Mohammed. On the bottom bunk, which was Mohammed’s, his father has created a small memorial for his late son: A photograph of the dead boy lies on the pillow, along with a checkered shirt, blue and black, that he liked; his schoolbag; a tennis ball; and...