"Thanks Sherlock, you've been a great help. You too John," Greg Lestrade runs his fingers through his grey hair, watching police officers swarm around the criminal and whatever evidence they can find, "we've got it from here, so you can both go home," he eyes the growing bump on Sherlock's forehead, "and, relax for a bit would you? You've been after this guy for five days and you're lucky John found you and disarmed him before he did something worse than hit you."

Sherlock sighs dramatically and spins around without a word, marching toward the end of the street.

"Thanks Greg," John says before jogging away to catch up with the long legged detective.

They manage to flag down a taxi and travel in a companionable silence; Sherlock texting and John watching London pass by, occasionally glancing over at Sherlock. He couldn't help but notice the bright pink lump on Sherlock's head where the criminal had hit him with a stray piece of wood.

His doctorly instincts started kicking in by the time they get back to Baker Street and he insists that he would have a look before doing anything else. Sherlock tuts but obeys quietly, the adrenaline and caffeine rush for the previous few days were starting to drop and he quite frankly couldn't be bothered to argue.

"Right, coat and jacket off and go sit in the bathroom," John orders as they get into the living room, "I'll be through in a minute."

Sherlock shrugs off his coat and suit jacket and throws them onto the sofa before shuffling into the hall while undoing the first button on his shirt, uncharacteristically silent. John, slightly taken aback by how quiet Sherlock was being, especially after a case that big, steps into the kitchen and picks up the first aid kit he keeps handy for occasions when one of Sherlock's experiments go wrong and promptly walks to the bathroom.

He finds Sherlock sitting on the floor, leaning against the side of the bath tub with his head in between his knees.

Sherlock hears John enter the room and lifts his head slightly and mumbles, "I'm fine," before pushing himself to his feet and teetering to the closed toilet lid.

That's when John sees the small trickle of blood just under Sherlock's hair. John rubs his face and sighs.

"You were just hit across the face with a chunk of wood. You are not fine, Sherlock."

"Fine. Dizzy."

"Yeah, you will be. For the reason I just said."

He stands in front of Sherlock and peers into his face, trying to gauge the damage to his forehead, "looks like you'll be fine. It's just a graze and a bump really, some paracetamol and a good night's sleep should do you a world of good. You'll stop being dizzy after a lie down. You don't feel sick or anything do you?"

Sherlock grunts in reply and slouches, which John takes as a no and Sherlock's way of saying to just get on with it. He balances the first aid kit on the sink and sprays some antiseptic on a cotton wool ball. As he dabs at Sherlock's head he continues, "From what I can see it's hardly anything, the bump'll go down in a few hours. But I want to check the rest of your head, just in case."

Sherlock winces at the sting of the antiseptic but doesn't speak, so John assumes he should just keep going.

He cleans up the cut, and is silently happy that he hadn't found any splinters before putting down the cotton wool and saying, "I'm going to check your head now. Tell me if it hurts."

John carefully runs his fingers through Sherlock's hair, checking for any more damage. This is the first time he's really been able to get this close to the dark curls when he spots something and suddenly stops moving his hands.

"What?" Sherlock snaps.

"It's... nothing. Just... your hair," John manages.

"What about my hair?"

He obviously isn't that hurt if he's already snapping at me, John thinks, "It's the roots," he contemplates for a second, "Sherlock? Do you dye your hair?"

Sherlock snorts, "Of course not, it's naturally dark brown."

"Really? Because your roots look very... auburny to me."

Sherlock is stony faced, "are you sure you didn't get hit on the head John?"

He pauses, "I don't care, you know. I mean, I've dyed mine before and it's not like I'll go screaming about it at Scotland Yard," he decides to change the subject and roots through the first aid kit for some paracetamol, "here, take these and go to bed. You'll be fine in the morning."

He packs up the kit and throws the cotton wool into the bin, just as he gets to the door Sherlock speaks.

"Thank you," he swallows the tablets without water and strides through the bathroom door, the dizziness obviously gone, and into his room, but not before flashing a small smile at John.

"Good night," John smiles.