It's the first really bitter night of winter, the cruel press of air like dry metal against John's bare skin. He runs, lungs wresting each breath by force from the stony blackness, feet aching with every strike against the pavement. Sherlock is still ahead of him, so he runs.
Then his body pitches forward, and his mind concludes, distantly: ice.
He lands hard. The raw wet scrape is a new kind of cold; he lies still.
"John!"
Leather gloves against his cheeks, smooth and cold, tracing the wound. Suddenly, Sherlock's mouth is hot against his; the world becomes visible again.