An excerpt from Remus's notes:

Day: 7

I had three coughing fits today. I coughed up four petals in the first two and five in the last one. I'm coughing up more blood each time. And the pain is getting worse, but nothing I can't handle.

"Lily better figure this out soon..." Remus thought as he rested the quill and ink on his bedside table and stuffed the parchment under his pillow.

He closed his eyes, knowing what to expect as he faded into the dream again.

This time, he took the path at a run. He looked down and realized it was made of black rose petals. When he looked back up, he was almost at the mystery person, and he stumbled in surprise. He could see them more clearly now- no not them, him. The mystery person was definitely a bloke. He could make that much out, but not really anything else. Dark hair, maybe. Mystery Man turned around and handed Remus a bouquet of Black roses he couldn't help but take. He inhaled the scent and fell through the floor once more.

"Moony- oh, you're awake," Sirius was standing over Remus, grinning. The little bit of light from the small window illuminated his features at just the right angle, and he seemed to glow. "Evans told us to wake you up and tell you to meet her in the library. No clue why, but she ran off before we could ask any questions."

"There better not be any funny business going on with you and Evans," James said suspiciously from across the room.

"I would never betray your trust like that, Prongs," Remus assured his friend. "I'm honestly offended that you think so low of me." He joked as he sat up in bed. He was worried that the other Marauders would have caught on that something was off about him, but all three of them had been absorbed in their latest prank. Which was probably why they were up at 7 AM on a Sunday.

Remus grabbed some clothes and got dressed in the bathroom. He had had at least four fits in this bathroom in the last week, but he'd cleaned it up with magic so hopefully no one would notice.

He bid his friends goodbye and hurried down to the library. It was mostly empty. He only heard two faint voices, so he walked toward them. Turning a corner, he saw Lily sitting at a table next to Regulus Black, a stack of books between them. 

Lily looked up and saw him. "Remus!" she exclaimed quietly. She got up and whispered to him. "I asked Regulus for help looking through some books I found on rare magical ailments. I told him it was for research though, because I didn't think you'd have wanted me telling people about your... problem. Anyway, we're looking for anything about flowers, and I think we're getting close.

Lily led him to the table. "Regulus, Remus is going to help look as well."

"Fine by me," The younger boy said, his face in a book. Regulus was apprehensive about Remus, I mean, Remus was best friends with Regulus's brother, but they had found themselves studying together in the library on multiple occasions and had formed a kind of peace. And then there was Lily, who could make friends with a brick wall and had often joined these study sessions.

They flipped through pages and pages of books for what felt like hours but was really only about thirty minutes. Lily had started looking during her free time, but she was also busy studying for her O.W.L.s and didn't get much time, so Remus was grateful for her help. Regulus thought he had found something, but it was some disease where flowers and mushrooms grew in your hair. Not what they were looking for.

After another quarter of an hour, Lily gasped. "I think I found it!" 

The boys got up and stood next to her, looking over her shoulders as she read aloud. 

"Hanahaki disease, which was first discovered and diagnosed in Japan, is a magical disease that is caused by unrequited, or one-sided love. The disease involves flowers growing in the lungs of the afflicted witch or wizard, who will cough up petals, which can progress to vomiting as the disease worsens. Hanahaki disease is, in many cases, terminal. The flowers will completely fill the victim's lungs and airways until they can no longer breathe. There are only two cures for this illness. The first is caused by the object of the victim's affection returning their feelings. The second option is a magical surgery that can only be performed by the most qualified of healers. The surgery removes all feelings of love for the object of affection, but in many cases, it can remove the victim's memories of that person or their capacity for love entirely."

"Well, shit," Remus breathed.

"You have it, don't you," Regulus whispered.

"Evidently."

Lily looked at him, her face a mix of worry and fear. "Remus, what are we going to do?"