John can see the black mood creeping in long before Sherlock himself even acknowledges it. It's not that there haven't been cases, it's nothing to do with boredom. Yet there it is, lingering, haunting, a darkness around the eyes, a tightness to the mouth, a slackness to his muscles when he's stretched along the couch staring at the ceiling. (And, Lord, but doesn't it hurt seeing him like that? Mask slipped away, revealing the numbness underneath.)
John makes tea, and watches as it grows cold because Sherlock doesn't even notice it sitting beside him, so engrossed is he in his own thoughts. The same thing happens to the pasta that he sets down, cold case files abandoned in a pile on the floor, unlooked at, ignored. (They may as well be invisible.
He doesn't bother turning on the telly, or even the radio in order to break the aching silence in the room. Instead, he kneels beside the couch, pulling Sherlock into his arms and hugging him. Finally the stare breaks, verdigris eyes shifting to take in John, and a faint, sad smile lifting the corners of those lips.
"Thank you," Sherlock murmurs, voice low and hoarse from disuse.
"Anytime," John answers. And they stay like that for a long time, pressed together, only sound in the room their even breathing.