A/N: A rewrite of the original Caffeine Equals Chaos, because I wasn't at all happy with how the original was left and I've got a hankering to rewrite it. Rewritten with Donna instead of Rose, because in my dream whoniverse she never left the show. Oh, and she's so much easier to write… just saying.

Also, apparently the original (with Rose) was made 3 years ago. Funny how time flies, ain't it?

Chapter One – Out of luck

She heard a curious ruffling beyond her magazine, and so lowered it.

"What is it now – has the beer ghost popped up in your tea?"

"No," the Doctor said, feigning innocence, "Why would the beer ghost be in tea? Besides; you and I both know he lives in Denmark, not anywhere on my TARDIS."

"Then what are you doing? Perusing the cover of Heat?"

"…We're out of teabags." he said, pouting.

"You know where the nearest Tesco is." she said, bringing her magazine back up.

"Do you remember the last time you let me go shopping on my own? You said you'd never make that mistake again."

"Good memory, but can't you drink something other than tea? Or surely you must have something that's a good enough substitute – coffee, maybe?"

His eyes seemed to widen considerably at that, "Oh, not coffee. Last time I had coffee I–"

"Do we have coffee?"

"Yes, but–"

"Have that then. A cup won't kill you."

He frowned heavily, and flounced into the kitchen. (Yes, he flounced.)

"Remember to clear up when you done!" she yelled down the corridor to his retreating form.

"Remember to nehnehnah I know what I'm doing!"

"Don't come crying to me when you somehow create a coffee bean monster using the toaster and half the utilities! I'm not clearing up your messes."

X-x-x-x-x-x-x

She frowned. It was quiet; too quiet.

He'd been out of the room too long; usually he'd pop up every now and then to let her know he was still alive, even if he was messing with the TARDIS' insides.

"You awake?" She yelled down the corridor; the door to the console room was down it somewhere, most probably open if he was working. There was no reply.

She went to search in all his usual haunts; The library, the spare parts room, and anywhere else he might spend his time. The TARDIS was helpful enough to move the rooms around so she could get to them in less time. He was nowhere to be seen.

She decided to check the place she knew he'd gone to last; the kitchen.

"Doctor?" she whispered, opening the door and walking in with caution. She'd no idea why she did these things; she had no need to be cautious, even if he wasn't in the room. "You better not be waiting to jump out on me. I'm in no mood for it, I can tell you that much." the lights were off, but even so – he could still be in hiding, just waiting to spook the living daylights out of her.

"DONNA!"

She turned to him. His eyes were manic and his grin was heightened to a certain mad degree. She put her hands in front of her chest in fear, but she didn't know why. "Yes, who else is here? And please lower your voice, I think the whole of the Milky Way just heard you."

"Donna, you've got to try this!"

"What, the coffee? Are you aware of how long you've been in here?"

"Oh come on, I'm highly alert!"

"Highly hopped up on caffeine, maybe."

He frowned, although he still looked like a caffeinated idiot, "You said to drink coffee, so I drank it."

"I didn't expect you to drink the whole pot!"

"I didn't; I only drank one cup. Didn't you realize what would happen if I drank any? You know I'm already a jumpy person most of the time, caffeine doesn't help matters."

"Doctor. You can't expect me to believe you only hand one cup."

"Seriously, I have! You can check the pot if you like. Caffeine makes me especially hyper in this incarnation; that's why I only drink tea. Last incarnation, I could quite happily hold it and not go off on one."

"It's nice that you're being very open about all this, but you need to sleep this off."

"I can't; once this crap starts it wont shut off."

"Can't you just give yourself, I dunno, some Horlicks or something? You've got to have something to aid sleep on this TARDIS, seeing as you're a doctor."

"I'm the Doctor, and I wouldn't dare inject any human sleeping drugs into my bloodstream; that stuff could kill me, and I don't think I have anything that will agree with my system and make me nod off."

Her eyes narrowed, "You seem fine now."

"The other things that caffeine does to me… I get mood swings. Very dangerous mood swings." he took a step closer; a rather menacing step, "it makes me… not a very nice person to be with. Really, you're in real danger. Your best bet is to get as far away from me as possible – and I don't care that we're on the TARDIS and I'm the only person who can pilot her, just do it. For your own safety, leave me to myself and let the effects wear off."

She took a step closer as well, "No chance, spaceman. Even on a bad day, you don't scare me."

Through the caffeinated haze hanging in his mind, she saw the real him appear on his face, but only for a moment, "I don't want to hurt you. And I will, if you stay with me any longer. The effects get worse before they get any better, and this is only the start. I consumed a whole cup, this could go on for hours. This time Donna I want you to be scared of me; that fear will make you alert and hopefully I wont be able to do anything to you."

Her voice shook as she spoke, "What would you do to me?"

"I don't know yet, but it can't be anything good."

"I've already said, no chance I'm leaving. I'll help you through this."

"Donna, another person in the room will just heighten the effects and they'll take longer to go away."

"Well, we're going to have to live with that, aren't we? I don't want you being on your own in the state your in. You're worried for my safety? You can't be in any less danger than I am."

He inhaled for a second, and encountered her scent; masked with fear. Of course, it made the effects start. "Donna, I…" with a sudden force, he wrapped his arms around her and pulled her body flush against his own, "…You really should've ran."

His husky voice sent shivers down her spine, "You don't scare me, you old softie."

"Old softie, huh?"

"Well, you are kind of in your 900s and a bit on the so–" she was heavily taken aback when he proceeded to bite her neck – hard, nearly drawing blood. Marking her, she knew.

"Am I an old softie now?" she could now feel the persistent bulge of his clothed erection against her stomach.

"I could say you're not soft in places now, mate, but you do know your boundaries." she replied, putting her hands on his chest in an attempt to push him away, but he just moved so he had her pinned against the countertop, with his arms on either side of her stopping her escape.

"Oh no Donna, because you know what else the caffeine does to my body? It increases," he ground his erection against her body, "my libido," he ground against her again, "tenfold. You sure you wanna stay with me now?"

She realized he was subconsciously giving her one more chance, a last chance to escape before he was lost completely, "I think I'll take my chances."

His lips crashed against hers, his tongue demanding entrance, and she knew he was lost. She decided to humour him, thinking it wasn't going to go anywhere and he'd come to his senses in a moment or two. She ground back against him, and he gasped, his eyes turning several shades darker.

"Donna…" he murmured, his hips bucking at the feel of her, "…do you know how crazy you're making me right now?"

"Thought you were already crazy."

"You know what I mean…" he moaned, pulling her to him, "…time to stop talking," he put a hand to the back of her head and caused their lips to meet, relishing in the silky feel of her ginger locks. He felt the need to feel her flesh on his, the need to be inside of her, "need you… now." He began to divulge her of her clothes, starting first at her dress.

He wasn't really going through with this, was he? She was really beginning to regret wearing a dress that day, never mind the fact he'd told her she should show her legs more. "Doctor," she tried to say, but it all came out as mush when he removed her dress and cupped her breasts through her bra. He fondled them experimentally, treating them with the same scientific curiosity he treated everything else that was new to him. Experimentally, he flicked a nipple, and she moaned as it hardened to his touch. She briefly wondered why she herself was getting turned on, but all thoughts left her mind as he moved to her other nipple and pinched it roughly through the fabric. He gave a non-committal shrug, still studying her reactions. When he felt he'd learnt enough from that area, he removed her bra with a flourish and set about devouring her left nipple whilst tweaking the other. Her breathing became ragged, and she put it down to natural reactions or some such nonsense. He was her friend and her his. She couldn't really want to sleep with him, could she…?

All questions left her mind as he grabbed the top of her knickers. She sighed, finally remembering that she'd opted out of wearing tights with her dress that morning.

He pulled her underwear down and off, and was assaulted with the thickening of her scent, "Oh, the plot thickens…" he let out a breath experimentally on her womanhood (being face level with it after removing her underwear), and felt a shudder of arousal pass throughout her whole body. He grinned and started licking her experimentally, relishing in the fact that she was already soaking wet for him. He smirked as her legs nearly buckled, but decided it was time to move, and she moaned at the loss.

He pulled her into his arms and lifted her up, carrying her bridal-style to her room, and laid her on the bed. He stepped back and studied her body in full, realizing he was making her feel uncomfortable. "You have no need to be embarrassed in front of me; I love your body," He began tracing a path down her body with his finger, "you delicious neck…" his path met her sternum, "…your luscious breasts…" he skirted round her womanhood, which she was thankful for, "and your… gorgeous legs." he then proceeded to lick his way back up her body, grinning manically when he was done. Her flushed face and flustered expression made him want her all the more. "Stop that."

"Stop what…?"

He put his mouth to her ear and breathed hotly over it, speaking huskily, "Stop being so sexy. You're only making me want to make love to you more, and I already want you too much for me to handle."

She smirked, and he could have sworn he nearly came in his trousers, "Then stop talking and take what's yours, spaceman."

He growled, and it seemed he couldn't shed his clothes fast enough. She gasped when she saw his throbbing erection leaking precum on the floor. She looked at his chest next – he might have been skinny but he certainly had no problems in the torso area. She could see him showing off as his muscles flexed under his skin. She looked to his arms, and they looked strong enough – strong enough, she'd realized, to pin her down in the kitchen and carry her to her room. She studied his legs – all that running did good for them, it seemed. "Your legs aren't half good – mine've probably got varicose veins."

He leaned over her, scrutinizing her, "Donna, you've got to stop putting yourself down. You're beautiful, and I'm going to show you that you are loved."

"Huh, for a second there I almost believed you."

"Believe it, Donna." He was stern in his words, and with one kiss she believed him.

A/N: …the next chapter involves Jack Harkness, which is fun! And it gives you an idea of what to expect…