"Now, there may be something wrong with my hearing Spock. I could have sworn that you just told me-"

"You heard me correctly doctor. Now, forgive my asking, none of my studies have ever informed me on this subject, do all human's posses this...ability?" For the second time in a row, Spock had managed to render McCoy completely speechless. All the doctor could do was give Spock this completely befuddled and confused look.

"No Spock, there has never been any case of a person being able to do that. Jim must have just been imitating the noise for one reason or another." As McCoy turned to get back to work, Spock's eyebrow rose.

"I assure you doctor, I've heard the noise before, this was not an imitation." McCoy stopped, turned back to face Spock again, and put his hand on his shoulder.
"Spock, I've known Jim for years, hell he was the first person I met at the academy. I can tell you right now, as his friend and his doctor-

-there is no way you heard Jim pur."

With that, McCoy once again turned around and got back to work, attending to a patient while Spock stood there, hands folded behind his back. As he walked out of sick bay and off to his quarters, he wondered if he really HAD heard Jim incorrectly somehow. It wasn't completely impossible after all. After a bit more thought, he decided to agree with the doctor. Maybe there really was something wrong with his hearing, if he had heard such a thing.

Once in his quarters, he looked at the clock. Seeing as it was half an hour past when he usually slept, he headed to the bed, sitting at it's edge as he took off his boots and pants. As he pulled the shirt off and over his head, he looked back, and gazed down at his sleeping captain. He had fallen asleep in Spock's bed yet again, and he slept just as he had each time, back to the wall as he curled up under the blankets.

As Spock sat, staring at his captain, he listened carefully for any sound, any purring.

...

Nothing but the sound of Jim's quiet, even breaths.

The vulcan nodded slightly before laying down, thinking to himself how tired he must have been to think that Jim had actually making such a sound. The corner of his lips curved upward slightly as he covered himself with the blankets and began drifting off to sleep.

But even after deciding how a strange, illogical thought it had been, Spock could have sworn he heard the noise again. The light purring that came from his captain as he nuzzled and smiled against his shoulder in his sleep.