As luck would have it, Sherlock was apparently nearly as irritable without caffeine as he was in the throes of a nicotine fit. John was suitably taken aback when he was abruptly awoken one morning by a looming, completely nude Sherlock barging into his room and demanding "tea, coffee, something, anything!" The fact that he was devoid of pants seemed to have escaped his powers of observation. Either that or he'd decided it wasn't important.

Grudgingly, John got up and dressed, without even bothering to shave or brush his teeth, if only to get away from Sherlock for a few minutes.

Making a mad dash through the supermarket, John grabbed what he needed. Without too much thought, he chose bag of ground coffee and several boxes of tea – some overly expensive and mildly unpleasant Lapsang Souchong for Sherlock, and good old PG Tips for himself. He eyed the self-checkout machine warily for a moment before ducking into a proper line with a proper human cashier instead; he didn't have the time or the patience to get stuck with a testy machine.

The woman ahead of him was taking forever, meticulously counting her change three times before losing track and starting over. Leave it to John to escape his mad flatmate only to get stuck in line behind some muddled old biddy.