"Alright! This time, we're all set to g—"

John stopped in the door frame of the kitchen. He was coming back from Mrs. Hudson's flat, where he had dropped off Rosie for an hour or two. Sherlock was still where he had left him – sat behind his microscope to look at a sample relevant to their current case – but he didn't appear to be working anymore. He was hunched in his chair with his head low, fingers clasped in his curls, his large back heaving.

"Sherlock?..." John called gently, taking a few steps forward. "Are you okay?..."

Sherlock didn't move right away, and it was only when John reached his side that he straightened up with a sharp intake of breath. "Yes! Yes, I'm… fine," he answered, quickly wiping a trail of tears off his cheek.

John felt his heart sink. "No, you're obviously not. What's wrong?"

The question made Sherlock's lips wobble. With a gulp, he fixed his glimmering eyes on an invisible spot in front of him and gathered his courage to reply. "I… I can't do it anymore."

John frowned. "Do what?"

"This," Sherlock gestured at the microscope, "all of this, solving cases, I…" He paused, his voice suddenly hoarse and raw. "I feel… diminished. I feel like my brain power is decreasing. I can't think, I can't… connect the dots. And it scares me…"

His last words had come out in a trembling whisper and left him on the verge of crying again, which was enough for John to rush and take him into his arms.

"Shhh, come here, come here…" he murmured as Sherlock buried his face in his shoulder, so openly and with so little hesitation that John got all fuzzy inside. "It's alright, we all have our ups and downs. You're been overworking yourself lately, and even you have limits. But it's okay, everything will go back to normal eventually. Don't worry, mmm?"

He rubbed his back and nape to try and soothe him, like he would with Rosie. Because that's how it felt, having Sherlock in his arms like this. And he loved it.

"What if it doesn't?..." Sherlock croaked, the sound muffled in John's shirt.

"It will, trust me. And even if it doesn't… You're not just a brain, you know? You're much more than that."

Sherlock gave a shaky breath and rested his chin on John's shoulder. "What am I?"

"Well…" John began, slowly breaking away to look him in the eye. "For starters, you are a very kind-hearted man; always ready to help those in need, whatever it takes. You're a patient little brother, and God knows how Mycroft can be annoying…"

The remark brought a smirk to Sherlock's lips, and inevitably to John's, who continued.

"You're a splendid violinist, an incredibly funny gent when you set your mind to it, a tough but fair movie critic… and a pretty good cook, as it turns out!..." he chuckled. "But above all: you're the best friend one could ever have, a wonderful parent for Rosie, and… the greatest companion I could hope for to go through this new journey with."

At this, Sherlock's jaw dropped slightly, and his eyes did that blinking thing John was so very fond of. "Do you… really think that?..." he asked, almost in a gasp.

"Of course I do."

It took Sherlock a few seconds to absorb every word John had said – along with every strong emotion they had aroused in him – but once he did, it was gratitude that settled on his face. "Thank you," he let out softly, looking more beautiful than ever.

John's chest filled with love at the sight. "You're welcome."

Both men gazed at each other for another while, enjoying the simplicity and intimacy of the moment, until John took it on himself to break the silence.

"Come on, we have a killer to catch," he said, giving a little pat on Sherlock's neck before grabbing his jacket off the nearest chair.

Sherlock sniffed and nodded, a bit more self-assured now. "We do."

"And I'll try my best to help you."

A gentle smile welcomed his comment. "You already did."

John paused in the middle of putting on his jacket, the same smile curving on his lips in response as he resumed. "Good to know." He beamed at him, tugging at his sleeves and adjusting his collar, then gestured at the door with a tilt of his head. "Ready?"

"Ready."

Their grinning eyes locking one last time, Sherlock reached for his own jacket and both set off.