A/N: I'm sure there's a ton a pirate!Sherlock stories out there, but I've wanted to do one since I saw Scandal in Belgravia. As always, any similarities to other stories are completely accidental.

Thanks to my beta, Gryphon31, for editing this.

Disclaimer: I don't own anything. Unfortunately.

The song Mycroft sings is Sleepless Sailor by Kate Rusby and it was my inspiration for this oneshot. It's pretty. You should listen to it.

"One more step, and I'll blast ye to smithereens!"

Mycroft sighed, pausing a few feet from his little brother. Sherlock aimed a toy gun at him, a wooden sword clutched in his other hand. While one eye was hidden by an eyepatch, the other was clearly alight with glee at his little game.

Mummy was out of town for the night, leaving Mycroft in charge of his sibling. The day had passed without issue. Mycroft had read his books on the lawn, occasionally glancing up to see Sherlock dashing about, making treasure maps and sword fighting with invisible foes. Now, however, it was well past Sherlock's bedtime, and the boy was being as difficult as possible. Mycroft had, perhaps foolishly, assumed that wrangling a five year old into his pajamas and into bed would be an easy task. Oh, how wrong he had been. The kitchen and bathroom were both in disarray, destroyed in Mycroft's attempts at dinner and bath time. He had been chasing Sherlock for nearly an hour now, trying to coax the boy upstairs to his bedroom.

"Parley." Mycroft announced calmly, holding his hands open in a sign of surrender when his brother's visible eye narrowed. He knew that Sherlock, dedicated to his pirate routine, would both understand and submit to the request.

"I am unarmed." Mycroft added quickly, hoping to speed the process.

Still appearing suspicious, Sherlock approached his brother slowly. He circled Mycroft, prodding him occasionally with his toy gun, as if to reassure himself that his brother truly meant him no harm. Mycroft released another long-suffering sigh as Sherlock returned to face him and finally lowered his "weapon." Too frustrated to wait for negotiations, Mycroft scooped his brother up, throwing the little boy over his shoulder, not caring if it was a breach of their parley agreement.

"Arrg! Lemme go, you scallywag!" Sherlock cried, his arms and legs flailing and pounding against his brother's strong grip. Rolling his eyes as he marched up the stairs, Mycroft wondered where on earth Sherlock had acquired such violent tendencies. Mycroft and Mummy were both docile as mice, while Sherlock was like a Tasmanian devil: a whirlwind of energy and mayhem. It must be all the pirate books the boy read.

Flopping his brother onto the floor, Mycroft proceeded to wrestle him into a pair of pajamas. Dodging the child's thrashing limbs, he ignored Sherlock's cries of "But I haven't found the treasure yet!" and "You'll walk the plank for this!" until he had his brother tucked securely in his bed.

Disregarding Sherlock's pout, Mycroft turned out the light. "Be quiet now, Sherlock. Even pirates need rest. Go to sleep." Mycroft headed for the door, only to be stopped by a small voice.


Biting back a groan, he turned back to Sherlock. With the light from the hall streaming in, Mycroft could still make out his brother's form, his eye patch still in place and his hand still clutching that silly little sword.

"Yes, Sherlock?"

"It's too loud in my head." Sherlock muttered, shifting restlessly under the blankets.

Mycroft nodded in understanding. While he generally viewed their incredible intelligence as a gift, it did have its drawbacks. Namely, that it was difficult to calm their racing thoughts long enough to rest. Unfortunately for them both, Sherlock desperately needed his rest. Mycroft had witnessed a sleep deprived Sherlock, and it was a truly frightening thing.

Returning to his brother's bedside, Mycroft gently removed the eyepatch from his brother's face and pulled the blankets up to his chin. Sitting beside the boy on the bed, Mycroft hummed softly as he considered what to do to help his brother. At the sound of the familiar tune, the little boy's eyes lit up, and he fixed them expectantly on Mycroft. Seeing his brother's look, Mycroft nodded in compliance. He cleared his throat and began to sing softly.

I once was a sailor, a young man and brave

Da da dum day, da da dum dee

My nights were once sleepless,

My peace I would crave

Carry me home to the sea

Da da dum day, da da dum dee

Drift away sailor boy on the deep sea

Worry no more for you're safe now with me

Rest in my arms and my sweet melody

Mycroft was by no means a wonderful singer. Yet his voice, deep and soft, filled the room and seemed to do the trick. Sherlock yawned widely, burrowing deeper into the blankets. The lines of frustration and concentration disappeared from the boy's brow, as his small body relaxed into sleep.

Oh rock me so gently now ocean so deep

Da da dum day, da da dum dee

I wish I was back, cause I think I can't sleep

Carry me home to the sea

Da da dum day, da da dum dee

Drift away sailor boy on the deep sea

Worry no more for you're safe now with me

Rest in my arms and my sweet melody

Satisfied with his brother's peaceful breathing, Mycroft stood. He gently removed the wooden sword from Sherlock's loosened grip, setting it aside on his nightstand. Moving to leave, he paused in the doorway once more to smile at his resting sibling. The boy was an absolute terror most of the time, but it was moments like this that reminded Mycroft just how much his brother meant to him.

"G'night, My." Sherlock's voice came, soft and sleepy, from the bed.

"Goodnight, little pirate."

A/N: I know the lyric is actually "sailor boys" but I thought it seemed better in singular form, since Mycroft is singing it to just Sherlock.

And I've tried everything I can think of to get this website let me put an extra space between the verse and chorus of this song, but it won't let me. Technologically challenged.

Please review!