He is very ill

You find Prince Sorrel in his room, confined to his bed. He looks completely pitiful, trapped under a thick fur blanket as he fights for each breath. His once tanned skin is pale and, when he opens his eyes, you can see how cloudy and confused they are. His father steps forward, leaning in to whisper reassurances as he gently pets his hair. The poor thing... You have no doubts that, if you can not figure this out quickly, he will be dead before the next full moon.

"You have a visitor Sorrel," he says softly, "Can you say hi?"

The boy doesn't seem to react at first, but then you notice his eyes slowly focusing on you. "Hello, my prince," you say, "Your father tells me that you aren't feeling well..."

Again, you don't get much of a reaction. Sorrel clearly doesn't have the energy to speak, much less move. You won't be getting much out of him. Instead, you turn your attention back to his father. You have a few ideas in mind, but any information he can give might help you identify the problem sooner.

"How long has he been like this?"

"He began to feel ill two months ago. It wasn't bad then, he only had a stomach ache then. Then he got tired easier and developed a fever. He's been bed-ridden since last week."

You nod, feeling a bit sick to your stomach as well. You've heard of these symptoms for multiple aliments, but the timing seems... Off. At least for something natural. Turning your attention back to the fawn, you begin your examination. Sorrel is very confused, unaware of what is happening around him. Again, you notice how pale his skin is, but now you notice the blue tinge of his lips. He's shaking as if he's freezing, but a quick temperature spell reveals that he's burning up. You frown as you continue to cast more spells. "What have the other healers said?" you ask, trying to find what to rule out.

"It's something they haven't seen before." the king explains, "At first they thought it was something he ate bothered him. The kitchen staff kept his meals simple for a time and he got better for a time, but then he got worse. When he began to get confused, they thought he might have caught a human illness. They tested his blood and ran spells to check his organs. All they could tell me was that his body was failing, but none of the illnesses they knew of were present."

You hum in acknowledgement, gears turning. Your own spells are returning the same results. "Did they test for outside factors?"

The king blinked rapidly at the question. "Outside factors?" he asked quietly.

"Like poisons." you clarify, getting more worried as each test points to an answer you don't want.

"They tested for some, I believe." he answered, unsure, "They assured me that there were no toxins."

You nod, casting another spell. This one isn't well-known in the Forests. You learned it from a traveling fairy who had been working with your mentor. It looks for poisons that are magic-made. They're practically invisible unless you know exactly what to look for. The light is a pure white at first, but then darkens into a deep violet mixed with strands of red. You sigh and turn your attention to the king.

"Your healers did the best they could, I suspect that their expertise is what allowed him to survive so far." you explain, not wanting anyone innocent to be troubled, "But what ails your son isn't something that they would have known to look for unless they worked with the Fae or another magical race. Your son has been poisoned, but not with natural, man-made, or faun-made substances. This, I believe, is caused by the Elixir of Twilight."

"He's been poisoned?!" he says, rushing back over to his son, "What... How...?"

"The elixir is something he would have had to ingest. I suspect that it would have been slipped into his food. It's slow acting, often showing as illness. If what you said is correct, whoever was poisoning him probably worked in the kitchen and was spooked when you asked the cooks to change his diet. There was probably not enough in his system when the symptoms started that he was able to fight it off for a time. When it started again and you thought it was illness..."

"They thought they could get away with it." King Aster interrupted, "We thought it couldn't be the food after it changed..." A moment of silence before he spoke again. "Is there a cure? Can Sorrel be saved?"

"We can save Sorrel. It will take time though. This specific elixir targets the magic of one's body, diminishing it until there is basically none left in the body. Then it will attack the blood and organs. We need to build his magic back, at which time he will be able to fight off the poison on his own. For now, all we can do is treat his symptoms and make sure no more poison enters his system."

"Will he be able to return to normal?"

"Honestly, I do not know. He's young, so I imagine that he will be able to recover better than others, but I have no idea how much damage has been done to him. His magic reserves may permanently damaged, he may be more susceptible to other illnesses. If the damage to his organs is too much, we may have to find a way to replace them. And this is if he manages to fight it off. I'm sorry King Aster, there is so much that I do not know about this. I would highly suggest you reach out to the Fae, they should have more knowledge on the subject than I, as well as more ideas to help."

The king nods before sighing. "Thank you for your help, Prince Forrest. I will reach out as soon as possible. Can I ask that, while we wait for a response, that you stay with Sorrel?"

"Of course, your highness." you say, "I'll care for him as if he's my own."