John yawned as he walked down the stairs for his morning coffee. Glancing at the couch, he stopped. Curled up on Sherlock's blue robe was a sleek black cat with a couple white patches.
"Sherlock," John called, looking back up the stairs.
"What?" Sherlock's voice answered, sounding slightly scratchy and much higher than usual.
"Since when do we have a cat?" John asked.
"Then why- where are you, anyways?"
"On the couch."
"...No you're not."
"Honestly, I think I know where I am."
"No, the cat's on the couch, but not... you..."
The cat's eyes opened and it sat up quickly.
"John," it- he- said, "What's going on?"
John sat down. Without a chair.
The cat looked down at his white-socked front paws, lifting one, then the other, in confusion.
"John," Sherlock said, "I'm a cat."
And he was. A black cat with a white splotch over his face and down his chest, leaving the black fur framing his face looking like his human hairstyle. His back paws and tail were tipped with dark gray.
"Sherlock," John said, "You're a cat."
"Yes, I think we've established that," Sherlock huffed.
"A talking cat."
Sherlock glared at John with gray-green eyes. "Will you stop being obvious, please?"
John nodded mutely, then shook his head. "You're a cat."
Sherlock rolled his eyes.
He extended the talons of one paw. "Claws," he muttered. "Could be useful..." he turned and raked said claws down the back of the couch.
"Hey! Stop that!" John said. Sherlock gave him a get-over-it look and continued. In his own time (thank you very much!) he turned away from the couch and leapt onto the table.
"Short little legs," he muttered. He leapt onto John's chair from the table, saying, "Jumping improved proportionally, in-context jumping height much decreased," then dug his claws in and pulled himself up to the back of the chair, regarding John, who was still sitting on the kitchen floor, speechless.
"I'm going to need new transportation," Sherlock said. "Get up, John."
When John still sat there, Sherlock leapt down and dug his claws into John's ankle.
"Hey-ow!" John said, swatting at Sherlock.
"Get up, I said!" the cat repeated.
Grumbling, John stood up. Sherlock immediately launched himself upwards, climbing swiftly up John to sit on his shoulder.
"You've got claws, now, you know!" Sherlock's perch said, wincing in pain.
"I know. It'll be rather nice, I think, being able to punctuate an order with a claw to the leg," Sherlock mused. "Well, then, John, forward!" Sherlock thrust a paw in the desired direction.
"...Where is it you want me to go?" John asked unhappily.
"Detective inspector's office, where else? I've got people to pester. I'm beginning to get bored."
John reached up and grabbed Sherlock, depositing him, protesting, on the couch. "I'm getting dressed first. Entertain yourself 'till I'm done."