A/N: Theta Sigma is the de-aged, amnesic Doctor. His personality takes after all his past incarnations, but the Tenth and Eleventh Doctor-ness are the most frequently displayed ones. And ooh, look, all his companions are looking after him! Fluff, humor and rudeness abound :)

Thank you for all your love and support, Momo Spock, Anaika Skywalker, shadowknight7580, Shadowdragon1317, dm1, Fall Out Bones Girl, Cure Eclipse, mp22mp22, Angelic915, Person, and Guest. Love yah! Let's begin, then!

Chapter 7

Remember Rule One

Morning

Donna bustled into the room with a silver tray in her hand. Jack, Rory, Amy and River also came in, chatting away quite briskly. Theta was sitting upright in his bed, propped against his pillows. He looked comfortable enough.

"Good morning!" He flashed a toothy grin, waving happily at them. Donna smiled, pulling a stool over and promptly sat down. She handed him the tray.

"Good morning, Theta. Here's your corn soup for breakfast!"

She beamed, handing the boy a bowl of delicious, steaming soup—upon which he immediately wrinkled his nose. He took a sniff, and looked up with pleading eyes.

"No custard?"

"No custard," Donna said firmly. "Come on, Spaceman! Custard cream is for dessert and snack only. And they are definitely not meant to be eaten with fish fingers, frozen bananas or jelly babies!"

"Awwww…" Theta whined, but dutifully drank his bowl of soup. After finishing it, he wiped his cream-laced mouth with his sleeve and muttered under his breath, "Stupid humans and their prejudice."

"What?" River asked back, raising her eyebrow in amusement. Theta—who didn't know that River Song was part Time Lord, and obviously didn't expect anyone to hear his snarky comment—startled and began shaking his head fervently, his eyes wide as a puppy.

"N—no, no, no, no! I didn't say anything, really! Nada! Nope!"

"Hmm?" Amy narrowed her eyes suspiciously. She turned her gaze at River, then at Theta, and then back to River. "River, what did he say? Tell me."

"Oh, nothing," the woman mouthed innocently. She turned to Theta, took a brief glance at her watch, and winked at him.

"I'm sorry, gotta dash. I promised to meet an old friend of mine at the café. I'll be back in an hour, sweetie."

"Oh, all right," Theta pouted, but still waved goodbye for her.

"Be back soon!" He called after her as she left hurriedly. River smiled and blew him a kiss, then disappeared from their sight. Rory and Amy, too, followed Donna out to have their breakfast downstairs, leaving Jack and Theta alone in the room. Silence ensued.

"…Boring." Theta sighed, his fingers incessantly drumming against his lap—but suddenly, his eyes lit up as a new idea occurred to him. He began tugging Jack's sleeve rather eagerly.

"Jack! Jack! Can I go out and play?"

"Play?" Jack asked, puzzled. "Play with whom?"

"Oh, the human children, of course!" The young Doctor was practically bouncing with excitement. "I've never seen human children—at least, as far as I remember. I bet they will be wonderful! Plus, it's too boring in here. Pleeeease, Jack?"

"Well…" Jack felt bad, really bad, staring into those begging eyes of Theta, but he had no choice. He shook his head heavily. "I don't think that's a good idea, Theta."

Theta's face fell immediately.

"…Why?" He asked, his voice the very image of disappointment and sadness.

"Because to us humans, your body—a Time Lord's body is a miracle. A cup of your blood could change history," Jack said slowly and seriously, gazing straight into the child's big brown eyes. "You might not understand, but there are very, very bad people and crazy men that would want to abduct you, torture you, use you for experiments and such—and when you were the Doctor, you could defend yourself. Now you are not. I'm sorry, Theta; we can't take risks. We don't know what might happen. I can't allow any harm come to you."

Theta's shoulders were still slumped. Jack fidgeted nervously, but continued in a brighter voice.

"You know, Thete, Mickey and Martha will bring a biodamper from UNIT tomorrow. If you put that on, it will cover your signals and make you safe. Then we will go out and play! How about that? I'll make it a really fun day for you. I promise."

"…Oh." Theta contemplated for a second, then brightened up again. He shrugged and said, "Well, there isn't any choice, is there? I understand. You are doing all this for me, so… what I'm saying is, it's all right with me!"

"Good boy!" Jack grinned and ruffled his hair. "I never knew that the Doctor could be this nice, though."

"Well, that's what the Doctor stands for," Theta giggled playfully, leaning back onto the bed. "Never give up, never give in. He can't help it if he's stubborn."

"Quite right!" The immortal man laughed and stood up, patting the boy in the back. "Just take a nap, rest, get some break. Or do you want me to stay and talk to you?"

"Mmm, actually—" Theta yawned and grinned. "I'm sleepy, Jack. I think nap is a good idea."

"Well then, I won't disturb you, Thete!" Jack laughed and heaved himself up. He affectionately ruffled the little boy's hair once more, winked, and hurried out of the room. He chuckled to himself as he closed the door shut.

The Doctor was eccentric, enjoyable, energetic, but he was quite rude from time to time, and had a tendency of ignoring others or keeping his feelings behind a smiling mask. But this Doctor—the young Theta—had all those quirky, cheerful parts of the Doctor that they loved, and was far more polite, truthful, and openly affectionate.

Oh, he would certainly enjoy his time with this brand new Doctor. River had provided him with a new Vortex Manipulator, which enabled him to stay here for the time being and go to Torchwood immediately if something terrible should happen.

Whistling, he happily marched down the stairs. Other people were having breakfast downstairs, and he thought he might as well join them, and help himself to some bread and butter.

DWDWDWDWDW

…Wait. Truthful? Of course not.

Rule One.

The Doctor Lies.

Theta's eyes flew open the moment Jack set a foot on the stairs. For a few seconds, he was completely still, listening intently for someone coming up the stairs to check on him.

All clear.

A crooked smile appeared on his lips as he danced out of the bed, purposefully grabbing a brown coat, a pair of blue jeans and sneakers, a purple shirt and a long blue scarf. He changed into them in the blink of an eye. Having that done, he tiptoed to the closet, and carefully combed his silky brown hair.

He frowned into the mirror as he found out that his hair had the weirdest tendency to stick up on all sides, like a crazy bedhead or something, in spite of all his combing. He thought for a moment, then simply shrugged the thought aside. Oh well. If it couldn't be helped, then so be it.

"A-ha. I knew it!"

Theta grinned, lifting his thick carpet and discovering the Sonic Screwdriver that River had hidden underneath. Holding the familiar device in his hand, he skipped over to the window. He dragged the stool along with him. Pausing briefly, he pointed his screwdriver at the bedroom door, locking it with a simple 'click'. Then he pointed it at the window, making it swing open. He grinned, amazed at his own abilities.

"Oooh, perfect!"

Humming, he pulled the stool closer, clambered onto it, and swung his body over the windowsill. At first he had been awkward with his moves, a stranger in his own body; now that he adjusted, he was nothing short of an expert. The decreased gravity only made it easier.

Behold.

Here enters Theta Sigma, one of the two worst troublemaking Time Tots in Gallifrey. The most daring, the most mischievous—and nothing but predictable.

"One, two…" He waved his hand in a dramatic manner, letting his body sway back and forth over the windowsill. And then he smiled.

"Geromino!"

He jumped.

Out the window and down, down, down he went, screaming in delight. It was three stories high, and he landed on the soft grass with a small 'thud'. His ankles ached and his wrists were sore from the impact, but it seemed to be intact—not a single bone broken or sprained. He winced, shaking his head and legs as he jumped back up. Soon, the pain dissolved, and he whistled.

"Woof, that was a rough ride. But it was worth it. Completely worth it!" Exhaling in relief, he finally took a good look around. It was his first time doing that; the last time he was out in the garden, he was so excited over the possibility of seeing a TARDIS for the first time in his life that he didn't have other this in life.

His face slowly lit up with amazement and disbelief. So green. So blue. So… lively.

Theta inhaled deeply, his fingertips tingling with excitement. I'm on Earth, all right! Mmmm… cinnamon, humans, rain, wet soil, fresh air, apples, and grass! Applegrass? No. Not applegrass. Just grass, and apple. Seriously, where did he keep getting those ridiculous terms?

He still couldn't understand many things. It looked like his adult self had made a stupid mistake, and his memories were erratic, and he often had flashbacks. But still—this was so cool. He was a hero, a true Doctor, brave and wise, traveling far and wide, with his very own TARDIS and a sonic screwdriver! Well… why did he sonic a screwdriver?! Freaky. Whatever. He didn't care too much. The important thing was, he was so far away from home; Irving Braxietel, his brother, would be jealous of him. He giggled nervously and wriggled his toes.

Ah, and there were friends. His friends. Much nicer and funnier than the mean kids at the Academy! They really cared for him and stuck to his side—although Jack felt a bit… wrong, he didn't quite know why—like a family. Like a real, true family. Hmph, he must be really happy.

On the other hand, there was that fuzzy memory of regeneration. Theta shuddered a bit. Why was he so lonely and desperate in that piece of memory? Where were all his friends at that very moment? He glanced at himself, feeling a bit unsettled at the thought—but it didn't last long. He shook that feeling off, and grinned again. Focus, Theta. You are on Earth; it's time to have fun!

He braced and shook himself, then began running.

He ran and ran and ran. The strange gravity made him feel exalted; the exotic greenery and fresh air was all new to him. He laughed out in delight, absorbing all the beauty that surrounded him—when he crashed into a blonde girl.

CRASH!

Theta was flung backwards from the impact, while the blonde stumbled only a little. He landed on the grass and rubbed his head, a little disoriented.

"Owwww…" He groaned, and looked up as the girl gave him a hand, looking concerned.

"Are you okay?" She said in a slightly apologetic voice. Wow, not annoyed at all? She must be really kind. "I'm sorry, I didn't see you coming."

"No, it's my fault. I should have been more careful," Theta smiled up at her, taking her hand and heaving himself into a standing position. The older girl smiled back. She was pretty and tall, well-balanced… in short, charming for a human (or so he thought). Her golden ponytail was quite long, long enough to reach her elbows, and, and…

Theta frowned.

Hmm, that was weird.

The moment he set his eyes on her, he was momentarily overwhelmed with a torrent of emotions, just like when he set his eyes on River Song for the first time, back in Donna's living room.

Grief. Sorrow. Loss. Regret. Loneliness. Joy. Pride. Amazement. Love, and warmth… just like a family. A real family. He felt this strange feeling that he suddenly had a lot to do, like, like…

'An awful lot of running to do,' he thought absent-mindedly, grinning at the familiar catchphrase. Irving, his brother, would always talk about such things.

Jenny studied him curiously. Theta fidgeted nervously under her scrutinizing stare, but it was she who held out a hand and introduced herself first.

"My name is Jenny, aged… well, I think I should say seventeen, to make things simple. I travel around all the time, just like my father does. And you?"

She smiled reassuringly, and with that, all doubt and uneasiness disappeared from Theta's mind. Traveling—when she looked so young! Wow, she was cool. Super cool. That was so impressive. He took her hand and shook it, a playful smile tugging at his lips. His childish mind had already forgotten Jack's warning to be careful.

So he said,

"My name is Theta Sigma, but you can call me the Doctor. I'm a Time Lord, I come from the planet Gallifrey of Kasterboros, I'm supposed to be over a thousand years old, thank you very much, but I think I was de-aged and lost some of my memory. Nice to meet you, Jenny. Is there any problem?"

Theta smiled innocently.

And Jenny's eye widened.

….Oh.

A/N: Sorry, it was a short chapter, but I'm updating fast, so I believe you will forgive me:) R&R please! It's 3 a.m. in South Korea! Encourage meeee!