kept whispering, ‘Don’t die. Don’t die. David, don’t die,’ as if I could talk him back to health. As if by sheer force of will, I could prevent him leaving us. Leaving me. ‘David. You’re my friend. Please don’t die.’ His lips moved and I leaned close to hear him. Faintly, oh so faintly, he said, ‘Knock … knock.’ I swallowed and said, ‘Who’s there?’ But he never spoke again.