Sherlock tapped his fingers together, lying on the couch. John was out with Mary, there were no cases; he had checked his phone several times in the past hour. Nothing. Absolutely nothing.

Which meant he was bored.

Normally the consulting detective would shoot at the wall or do an experiment, or even talk to Belle, John's friend who'd come round to stay for the month, but he actually liked the silence-

Wait.

What was that?

Abruptly, Sherlock sat up. He listened to the voice.

"...Alarming..."

For once, the smartest man in the room was completely stuck. He was dumbfounded. That couldn't be...no. Could it?

Slowly, he got up from the couch and quietly went to the guest room. He paused at the door.

"True, that he's no Prince Charming..."

The consulting detective froze. It was an amazing voice. Then, quietly, he opened the door a little and more, and more until he was standing with the door fully open, listening to Belle's voice. The young woman sat on the windowpane, singing to herself as she stared at the snow that was falling.

"But there's something in him that I simply didn't see."

Sherlock cleared his throat. "Miss Bougard."

"Oh! Mr Holmes!" She looked at him, surprised. "I'm sorry, I-"

"No, carry on," Sherlock said, gesturing with his right hand before putting both hands behind his back.

"Mr Holmes," she laughed nervously, "I don't think I can sing with you watching."

Sherlock's mouth twitched upwards, forming a smile, almost.

"Belle," he chuckled, "you have a beautiful voice, I must say."

The young woman flushed. "Thank you." She looked at Sherlock, who cleared his throat again.

"Right. I should leave you. Apologies Belle, do forgive me."

"It's alright Mr Holmes," she smiled.

"Please. Call me Sherlock." The consulting detective winked at her before closing the door.

Belle froze, blushing. Did he just...?

She shook her head before continuing to sing.

Outside, Sherlock heard her resume again, and for once in a long time, let a small smile creep onto his face.

Both he and Belle were definitely beyond formalities, and he had to say...that voice just made his day.