The first time it happened was certainly not to be the last. When you are such a brilliant man as Sherlock Holmes, you are bound to have some epiphanies at inconvenient times, but blurting them out over dinner, or shouting them out in the shower was one thing, having the brainwave while you are getting dressed in the morning is entirely another. He had just been putting his socks on (mundane things socks, yet brilliant men throughout the ages have worn them) when it occurred to him.
"Of course!" He grinned, straightening up and snapping his fingers. Disregarding his state of undress he hurried upstairs, flinging open John's bedroom door. The war veteran sat up in alarm.
"Sherlock, it's… 7am!" He complained loudly.
"Nevermind that." He said dismissively, striding in to the room. John blinked, having to do a double take, aside from his socks, the great Sherlock Holmes was striding around his bedroom completely naked. "It's so obvious! I can't believe I didn't see it before!" He said brightly, pacing a circle in front of John's bed, as though waiting for John to cotton onto whatever reel of thought he was spinning.

John sighed heavily.
"You do know you're naked?" He put forth, rather lazily.
"And you're in your pyjamas - I don't see what that has to do with anything." Sherlock said calmly. "The soufflés John! How did she make the soufflés!?" John looked puzzled, then alarmed as Sherlock turned to face him.
"What bloody soufflés? And would you put some clothes on please?" He stressed, feeling an uncomfortable pink blush settling on his cheeks. He was grateful for the fact that if Sherlock had noticed it (and he had) he said nothing about it.
"Don't you see!?" Sherlock ranted. "There's no milk!" John rubbed his forehead with his hand, stood up and grabbed his night gown from the back of the door. He threw it at Sherlock, who caught it rather clumsily (he would certainly at a later date berate John's timing, he did not focus well on the physical aspects of catching an item while he was thinking, or rather applauding himself on his way of thinking). Sherlock threw it on absently, grabbed John's hand and dragged him down the stairs into the living room.

"Sit, see." Sherlock insisted, pushing John into his usual chair and turning the television on, unpausing it at the 'next week on' segment they had frozen it at last night whilst Sherlock deduced the plot.
"Doctor Who…" John said, bewildered. "You woke me up at 7am, walked into my room completely naked to tell me you'd figured out the plot of the next episode of Doctor Who!?" He asked incredulously.
"Brilliant I know, the man said it himself - it's all about the soufflés!"
"I'm going back to bed." John said with a sigh, and stood back up. Sherlock looked alarmed. "You're a mad man, Sherlock Holmes."
"John, don't you want your robe back?" Sherlock offered, and when John turned around to say no he realised Sherlock was standing there, naked again, handing him his robe.

"She was or should I say will be a Dalek all along, by the way." He said proudly as John rather reluctantly took the robe.
"You got all that from the preview?" John has long since learned not to act so amazed at Sherlock's discoveries, it gave him an over inflated ego, and the smug look on his face was just wrong when he stood there naked apart from his socks. "Well, we'll see next week won't we." John said in as kind a voice as he could possibly manage, leaving the room.

The next Sunday, Sherlock arrived in his room at around the same time, in a similar manner of undress.
"Full of historical inaccuracies." He grumbled, pacing around the room. John sighed heavily. "And the practicalities of it - honestly! Unchecked they'd run amuck and eat each other, and where would all the poo go?"
"Sherlock!" John snapped irately, when Sherlock kept talking John got up, out of bed and approached him.
"Not to mention the mechanics behind the ship, basic scientific principals of…" John stood directly in front of him, toe to toe. "Weight and propulsion…" Sherlock continued, but his voice had become strangled and harsh, it was unlike his friend to get so close, his eyes seemed to be boring straight into him. "Do you mind, that's rather off putting. Distracting if you will."
"Oh I'm a distraction, bit rich coming from you." John said, evidently still annoyed.
"Ah, bad timing?" Sherlock asked cluelessly. John raised a single finger to Sherlock's lips, Sherlock nearly went cross eyed staring at it.
"You can't just burst into my room at 7am every Sunday - naked." John informed him.
"Ah, okay… very well then. Right… I'll be off then." He turned on his be-socked heel and left John's bedroom. John stared after him in shock. That had been too easy.

The next Sunday John was only half surprised when Sherlock burst in, naked as ever.
"I thought we discussed this?" He said tiredly.
"It's 7.15." Sherlock said as though that explained everything. "The electricity in the mid-west…" He started. John just rolled over to face him while he ranted and raved about next week's episode. If John had to put up with this every Sunday morning, he could at least lay back and enjoy the view.