Professor Dumbledore was surprised when the young Miss Lovegood arrived in his office.
"Good evening, Miss Lovegood," he said with an indulgent smile as the girl wandered his office.
"Good evening, sir," Luna replied, seemingly unable to keep the wonder out of her voice as she mentally catalogued the various tools and decorations. "Do you know where Mr. the Doctor is?"
"He is with his TARDIS at the moment," Dumbledore answered, wondering (not for the first time) at how the Doctor had befriended the eleven-year-old Lovegood girl.
"Hm. He'll want to be alone, then," Luna said sagely.
"I imagine so." Dumbledore noted Luna's somewhat melancholy demeanor. "Is there something you wished to discuss, Miss Lovegood?"
She looked at him, then, for the first time. Her eyes were wide and deeply thoughtful, and something deep inside of Dumbledore prickled for a second, reminded of a different young girl with similar hair and eyes just as full of innocence...Poor, poor Ariana. Not his very first failure, but his very worst. "Sir," Luna began, "could you tell me what you know about...the Come-and-Go Room?"
Dumbledore had not been expecting the question, but he did not allow his confusion to register in his expression. "The Come-and-Go Room, also known as the Room of Requirement, comes equipped with the seeker's needs. An individual in search of a toilet would find a lavatory. A person plagued with exhaustion would find a bedroom. To get it deliberately, though..." He trailed off, eyes focused on Luna.
"I'd have to walk back and forth in front of a wall on the sixth floor, thinking about what I want the room to become," Luna finished for him lightly.
"Is something amiss, Miss Lovegood?"
"No, sir." She offered him a hand, which he shook. How many students had offered to shake his hand over the years? He couldn't help but to feel amused by her strangeness. "Thank you for speaking with me. Your phoenix is very pretty."
...
With Tom's instructions, the Come-and-Go Room was easy enough to find, and soon Luna sat atop an old cabinet, dangling the time-turner from her fingers, holding it in front of her face as though trying to hypnotize herself.
I'm not going to do it now, of course, Luna thought. Not until I've spoken with Mr. the Doctor.
She couldn't quite convince herself to go see the time lord, though. After all, he was awfully concerned about his TARDIS, practically in grief, and Luna was not sure that she wanted to see Mr. the Doctor in grief. She didn't quite know what it was, but something about the idea made her a bit ill, and it made her think about her mother. There were so many connections there: her mother and her father, her mother and the Doctor, the Doctor and his TARDIS...
Luna put the time-turner on and opened Tom's diary on her lap. Did you ever know your parents?
The answer was immediate: No. Did you get the time-turner?
I have it.
Come.
Not yet.
Lovegood, enough games.
I'm not playing a game that I'm aware of. I'll come when I know I have a way back home.
It took several seconds for Tom's reply to start appearing, and the change in tone was immediately noticeable; his handwriting had returned to its original neat, even loops rather than the hurried, agitated scrawl it had been moments ago. Fine then. Tell me about your parents.
Wary but serene, Luna wrote, My mum died when I was nine. She was a great witch, but now it's just my dad and me.
Do you love your father?
Oh, yes! He's a great man. Since when are you so curious?
Tom ignored her question and kept firing out his own: How were things after your mother died?
Luna froze. Then, she managed to write: Awful, of course.
Tell me about it.
Dad was miserable. I wore my funeral dress for a very long time, but otherwise I tried very hard to keep things light and warm. Once she started writing, she found she had to explain herself further, to make him understand. He was so unhappy, you see. He never stopped loving me, but I do think for bits of time he sort of forgot he had a daughter. But that wasn't his fault. He loved her so much, it was like she took half his heart away with her. So I had to take care of him for a while, because he forgot to take care of himself. At last, her quill went still. She had splashed tiny drops of ink on her knees and hands.
And you, as well? He forgot to take care of you? He forgot that you were hurting, too?
Luna was surprised when a tear ran down the side of her nose and landed on the diary's page. Then another followed.
You're crying.
Luna set her quill down. Her hand was trembling.
Careful, Tom added. One's emotions often render one highly susceptible to influence.
The word "influence" swam before Luna's eyes, and a panicked part of her had the irrational need to shut the diary straight away, but instead her vision began to go dark.
The last thing she remembered before she blacked out was feeling her hand close around the time-turner without her permission.
...
"Lovegood!" The Doctor sprinted noisily through the halls of Hogwarts. "Lovegood!"
He collided, as luck would have it, with Professor Snape.
"Oi!" he exclaimed. "Severus! Have you seen Lovegood?"
"Not since her disastrous display in my classroom," Snape replied, his dark eyes scanning the Doctor up and down.
"Right. How long ago was that? Don't answer; doesn't matter." The Doctor resumed sprinting. Dumbledore had told him that Luna had been inquiring about the Come-and-Go Room; he would simply meet her there.
He conjured the Room of Requirement as the room of hidden things mainly because it had been such a significant part of the books. He entered amongst the piles of items.
"Lovegood?" he called. So she wasn't here. Well then, he would have to check som-
Was that the vanishing cabinet from book six?
No, no, he wasn't going to get distracted; Lovegood first, cabinet later.
He would have to check somewhere else.
At that moment, an idea hit him that caused him to grin: Who did he know with a map of Hogwarts and everyone in it?
Exiting the Room of Requirement, he again broke into a sprint and shouted through the halls of Hogwarts, "Weasley twins! Weasley twins!"