There was a curious feeling building up in his midsection. Not entirely painful, no…But not entirely pleasant either. It was somewhat discomforting.

Strange, the human body. When he had been a Time Lord (or rather, when he remembered his other self – very odd to have two selves, really – being a Time Lord), he had rarely felt such discomforts. His superior Time Lord physiology had compensated for all of that. Except for that one time when his regeneration had been interrupted after the incident with the time vortex. Or the time he had changed every cell of his Time Lord body to that of a human. Or, he shuddered violently, the time that Jackie Tyler had thrown herself upon him and kissed him. That definitely had to be classified as "discomforting". Or perhaps horrifying. Yep. Horrifying was definitely the word. It had been a horrible, horrifying experience. A horrible horribly horrifying experience. A horrible horribly horrifying horrendous experience. He quite liked the sound of that.

As he turned to parrot his new favourite phrase to Rose, he felt the discomfort in his midsection intensify.

Was there something wrong with his human body? He had felt perfectly fine before. Maybe something had gone wrong that he (and his other self) had not brilliantly thought of? Was it an after effect of the regeneration? It couldn't be…but then again, he had met very few people (other than himself) who had spontaneously generated out of a preserved severed hand and a human being.

"Rose…", he croaked out, the feeling becoming unbearably painful, "I think something's gone wrong".

Rose rushed over, her eyes wide with fear and concern. But before she could do as much as say his name, it happened.

A low, thundering rumble erupted.

From the Doctor's bottom.

The Doctor opened his eyes, blinked and then beamed at a rather horrified looking Rose.

"Oi! That was brilliant! Who knew that you humans – I suppose that includes me now, one heart and all– could produce such magnificent noise! And it feels brilliant! Just brilliant! There's something else that could be said about the smell", the Doctor sniffed, wrinkling his nose, "But I suppose – Can you do it too Rose? Fancy a contest? A concert? A concerto?"

The Doctor strained, pushing out another rumble which ended in a forceful, high pitched squeak.

"Did you hear that Rose? Ohhhh! Brilliant!"

Later…

Perhaps not so brilliant, the Doctor thought glumly. Not if it meant sleeping on the couch.