We met Allah Rakha as he sat in the shade of a tree, in a small public garden in the heart of the Pakistani city of Lahore.
His silvery hair and his beard were neatly trimmed. But his clothes were dirty, his eyes half shut, and his speech slurred.
"These days, when I inject drugs, there's a queue of people behind me, waiting to use my syringe," he tells us. "We know about Aids, but when you're desperate for a hit, you'll use anything that's available."
Close by, other addicts were openly injecting. Between uses, they washed their syringe only with water from an old soft-drinks bottle.