During the months he had lain flat on his back in the dark, trying not to be sick from vertigo, sometimes the sun would come out from behind clouds. Even through the blackout curtains next to his hospital bed, he could sense that it had done so. Not so much because of light leaking round the edges as because of the vague omnidirectional warmth radiating through the dark fabric. This was a little like that. On the dark side of the neurological curtain was Laks, trying to work out what "social media" denoted. On the other side was a large portion of his brain. And yet the curtain had a few moth-holes in it. Through those, he glimpsed clear images: a freckle-faced woman with a camera. The snowy top of a mountain. A Chinese man with a stick.