"What a marvellous switchback!" Lenina laughed delightedly. But Henry's tone was almost, for a moment, melancholy. "Do you know what that switchback was?" he said. "It was some human being finally and definitely disappearing. Going up in a squirt of hot gas. It would be curious to know who it was-a man or a woman, an Alpha or an Epsilon..." He sighed. Then, in a resolutely cheerful voice, "Anyhow," he concluded, "there's one thing we can be certain of; whoever he may have been, he was happy when he was alive. Everybody's happy now."