Newton's Laws

~ Written for the prompt 'Newton's Laws' for neth_dugan.

It was weird, walking into the TARDIS at a normal pace, closing the door and sauntering over towards the control panel. No last-second dodging inside, grateful for the forcefield that would protect them from the weaponsfire.

Jack paused, watching as the Doctor sedately put the TARDIS into motion. He nearly reached up to put his hand over his heart to make sure it really wasn't pounding with adrenaline. He caught Rose's eye and she grinned at him.

"Doesn't seem right, does it?" she said, reading his mind -- or at least even more used than he, to the Doctor's usual mode of exit.

Jack laughed. His reply was interrupted, however, by the Doctor clapping his hands together, the slap echoing loudly despite the odd whine of the TARDIS' engines.

"Right then," the Doctor said, giving them each a look. "Now that we're on our way, I'm going to head down and put Newton's Second Law into action." He turned and walked away; neither Rose nor Jack followed.

Instead, they looked at each other in confusion. Rose frowned, biting her lip. "Newton's.... Is that the one where a body in motion stays in motion? No - force equals mass... times something...." She glanced at Jack, clearly hoping he knew what the Doctor was on about.

"Doesn't make sense." Jack shook his head. "Unless he has a billiards table down there which... come to think of it, he might. But... oh!" Jack suddenly remembered an old lesson from school. He found himself smiling and he took Rose by the arm, gesturing graciously towards the doorway the Doctor had disappeared through. "I think he means Rachel Newton's Laws of Etiquette, first published in 2391." He held up a finger, quoting his teacher, Mrs. Dabney. "Law number one -- always send <i>personalised</i> thank you notes for gifts received. Law number two -- A good host or hostess always provides a full service shower for their guests."

Rose narrowed her eyes. "You're joking. There's Laws of Eti-- wait, number two, a full service shower?" Her eyes grew wide, and she turned to stare after the Doctor.

Giving her arm a slight tug, Jack pulled her along beside him and walked away from the control room. "He could be talking about Gorshack Newton's Laws of Planetary Invasion, but there's one quick way to check. If we find him in the bathroom, it's Rachel Newton."

"And if he's talking about Gorshack?" Rose came with him easily enough, an eager grin appearing on her face as she apparently decided Jack was most likely right.

"Then you and I take a quick -- or long -- shower, have a nap after, then suit up in mobile body armor and help the Doctor take over a planet."

She giggled, then grabbed his hand. "Come on, then!"

Jack had to hurry to keep up with her. When they reached the door to the bathroom, Rose hesitated only a second before placing her hand on the panel. The door slid open and the wet heat of steam hit their faces at the same time the sight of the Doctor, naked and waiting patiently, hit Jack in places considerably lower.

"And I was looking forward to ruling my very own planet," Rose said, frowning. Jack gave her a shove towards the Doctor; she stumbled slightly, caught herself only to take one more step forward and be caught up by a man wearing only a towel -- over his arm.

"We can take over a planet tomorrow if you like," the Doctor said, then he gave her a kiss.

"Can it be Molicar-shigachican?" Jack suggested, dropping his clothes on the floor as he watched them. If he ever met Rachel Newton, he was going to buy her some very expensive jewelry.

The Doctor gave him a mischievous grin. "Can be, if you're a good boy."

"I thought I had to be *naughty* to go to a place like Molicar-shigachican," Jack said, grinning in a not-quite leering way. He stepped up to take Rose's place as she slipped back out of the Doctor's grasp, and Jack claimed his own full-service kiss.

"What's Moliwhatever?" Rose asked, and Jack broke free just enough to look over at her. She was watching them, eyes growing unfocused in exactly the same way that Jack's own did when he got to watch.

"Pleasure planet," the Doctor said. "Very popular with the tourist trade in the 52nd century. We should go, sometime, when we've built up our stamina."

"Built up our--" Rose stopped, and her jaw snapped shut with an audible snap. She eyed them both. "So you're saying we need more practise?"

"Well, technically my stamina is just fine--" the Doctor began, and Jack took that as his cue.