ARACHI, Pakistan — The nursery where they killed him, one year on, is oddly peaceful. Lush mango, palm and pomegranate trees are in bloom, their thick, green leaves whispering in a gentle breeze.The cinder-block storehouse where he was executed is empty, save for some flower pots, a cot and crumpled packs of cigarettes strewn across the floor. The 10-foot by 15-foot main room still has a metal door and metal shutters that can be padlocked. Sounds of life reach the room: birds chirping and cars driving past to a nearby religious school run by Al Rashid Trust, an organization...