After talking to the Doctor, the solar monarch made a deal with him. That she will pardon him, his companions and his wife from the accounts of trespassing, damage to royal property and vandalism if they can somehow cure her sister of her nightmares. But until they succeed, they shall be kept under a watchful eye of the royal guards.
What his companions found interesting about this very young Luna, was despite living in a castle that has many darken hallways, Luna was what one might call, a scaredy cat. Literally, everything that moved or made the slightest sound made her jump. She always stayed close to River, hiding behind her from everything.
The very first place they headed towards for their investigation was Luna's room. The stony room had what any other child had. A blue bed with curtains to match, a toy chest, a vanity table with a mirror, and scattered all along the floor here and there were piles of paper, pencils and a wide range of chalk in many different colors.
“Well then,” -the Doctor said looking at the drawings- “I think we're getting somewhere.”
“I didn't know you drew, Princess.” Tick Tock said picking up a drawing of what was outside her window.
“I'm not a princess.” Luna said melancholy, “I don't even have my cutie mark.”
“A cutie mark?” River asked. Luna was taken aback from her question.
“Don't you know what a cutie mark is?” she asked. River tilts her head to the side. “I just got her less than an hour ago and I've been given a brief explanation of what your, uh, planet is like.”
“Oh, well, a cutie mark tells what your special talent is,” Luna said. “In fact, you've got a cutie mark.”
“Where?”
“On your flank silly.”
River looked around her and, sure enough, on both sides on her flank on her new pony body. “A blue question mark? Huh, how fitting.”
“Excuse me Luna.” the Doctor said, getting their attention. “Do you ever draw out your dreams?”
“Sometimes.”
“Do you still have those drawings?”
Luna nodded. “I put them in the bottom of the toy box.”
“I'll get it!” Ditzy said, opening up the chest. Underneath some wooden toys and hoof stitched dolls, she found what they were looking for. She picked them up with her teeth and spread the drawings on the floor.
Although the drawings were crude, each picture was drawn in mostly black chalk with glowing eyes in reds, yellows, and greens. Some portray veracious animals, others were very tall and wore cloaks. Some had horns, others had bat wings and so on. Yet what all of them had in common is that behind all of them, there's a dark gray mist that spiraled and curved around these nightmarish drawings.
“Well, well. Tim Burton eat your heart out.” River said aloud. Ditzy, Tick Tock and Luna looked at her confused.
It was Ditzy who asked the question on their minds: “A Tim what?”
River shook her head: “Never mind, he was an artist that I used to know. But as of right now, we've got work to do.”
“Agreed.” said the Doctor, quickly looking through the drawings. “So Luna, how long have you had these dreams.”
“For fifteen nights straight.”
“And have you've seen anything unusual?”
“Like what?”
“Oh weird things, like flashing lights, shadows, disembody voices, things like that.”
“Well I, don't think so.”
“Or has anyone disappeared lately?”
“Not that I know of.”
“So it's only just dreaming then?”
Luna nodded. The doctor then took out his sonic screwdriver. “Fascinating. Now Luna, this here is-”
“A sonic screwdriver,” Luna said, which took both the Doctor and River by surprise.
“How did you know that?” the Doctor asked.
“Um... I–I can't really tell you.”
“And why not?” River asked.
“Uh, spoilers?” Luna said adding an uneasy smile.
“Okay then. Anyway,” -the Doctor continued- “what I'm going to do is simply scan you to see if there's anything wrong. Don't worry, you won't feel a thing.” The doctor did scan the young Luna, when he looked at the results, the only thing he could say was: “Oh...”
“Oh?” Ditzy asked, “What kind of “Oh” are we talking here? Is it “Oh that's interesting” or “Oh that's bad”?”
“Both. It says that Luna has more than one consciousness. She has several- no! Many. Luna, please hold still.” And with that, the Doctor put both of his hooves on the sides of her head. Both he and Luna closed their eyes. Within a few seconds later, the Doctor quickly drew away from Luna.
“Oh no. Oh no, this is not good! Not good at all!”
“Doctor, what did you just do?” Tick Tock asked.
“I entered Luna's mind for just a moment, now I can see what we're dealing with. I've only heard of these in a few legends, but I never imagine we would encounter them until now.”
“D-Doctor, what are you talking about?” Luna asked, “You're scaring me.”
“Actually my dear, when there's a small army of Hunllefau's that is just waiting for you to go to sleep, you've had every reason to be afraid.”
“The what?”
“I've heard of this legend too.” River said, “Although the name itself does variate from planet to planet, basicly it is said that these were spirits that feed off of fear by giving nightmares. The more they feed off of that fear (or well, any kind of negative emotion that produces fear) the more they act like a parasite. Where in the end, they just take control of the victim to spread more fear.”
“Yes, but they only can give nightmares when they are asleep, until then, they can't do anything until they feed off enough fear to take control.” The Doctor said with an agreement. “But with Luna, this isn't your average feeding frenzy, this is a full out war that's going inside her head every night. Each and every Hunllefau is fighting for supremacy over the others to gain absolute control of Luna. Tick Tock, I'm going to need your expertise.”
“Expertise for what?”
“We are going to invent a machine that links conciseness several millenniums early.”