Luke staggered through the bathroom door, heading back into his dim bedroom. Traces of brightness cut through the blinds, preventing a complete black-out because of the city lights. He'd never considered installing a heavier window covering though, because he knew it would make him feel like he was suffocating.

The man didn't need to check a clock to know that it wasn't time to get up yet. As he crawled back into bed however, a red light drew his attention to the nightstand. Luke's brow furrowed while he picked up his medical scanner, one of three identical machines that Donatello had designed for them. He'd gotten into the habit of leaving the device turned on while it was charging at night. The fact that the light was flashing could only mean that some alert was crying out for attention.

Luke sat up against his headboard, scanning the main screen of the machine with bleary eyes. He was startled to find not one, but several medical flags. "What?"

He reached to turn on his lamp, instantly wider awake. Blue eyes squinted as he identified the source of the red flags. Raph? What in the world? The man sifted rapidly through screens, speed-reading at a rate that it made it difficult to comprehend all of the text. The two things that immediately stood out to him were the red-masked turtle's increase in temperature and decrease in oxygenation. What kind of insanity is this? Why didn't anyone call me?

Luke dropped his scanner on the bed and grabbed his cell phone, noting the time as being a little after 5AM. He clenched his jaw in irritation as he dialed Donatello.

"Hello?" the purple-masked turtle answered warily.

"I just logged on," the man said testily. "What the heck, Donny? Why didn't you pick up the phone?"

"I was going to. I just…I thought I'd let you get some decent sleep first."

"Raph's bordering on 105 degrees!"

"I know, Doc. The hydralin isn't making a dent."

Luke groaned in utter frustration. "Donny!"

"I wasn't trying to take on everything alone. Only one of us needed to take a shift at a time, and Marc is already here—"

"You called Marcus and you didn't call ME?"

"Doc, it's not what you're thinking! It's way more than complicated than that. I'll explain everything, but it would probably be easier in person."

"That's convenient, because I'll be on my way down in ten minutes."

The doctor was still burning with fury when he made it to the den, but a little of his anger faded when Donatello met him at the door with downcast eyes. "Where's Marcus?"

"Asleep with April in the lounge."

Luke laughed mirthlessly. "How did I end up being the only one left out of the loop?"

"Come with me, Doc," the turtle said quietly.

The man needed no further prompting, and quickly followed behind Donny as he led the way into the lab. Luke stopped in his tracks upon first seeing Raphael. He hadn't expected to find the older turtle bereft of his mask, with his head partially wrapped in gauze.

"Donatello, what happened to him?"

"It's sort of a long story, so I'll start with the short version. Raph got into trouble on the surface last night. The reason that Marc is already here is because he ended up in the middle of it too."

Luke shook his head. "That doesn't make any sense; no more than this strange drop in his oxygen levels."

Donny shifted uncomfortably from one foot to the other. "It isn't critical yet, but I've been watching it. It sounds like fluid is accumulating in his lungs. Raphael has a lot of the classic flu symptoms, but he isn't coughing. I expect that could have something to do with it?"

Luke eyebrows rose as he digested what Donny had just told him. "I need to have a listen to his lungs myself." He knew that the slightly labored quality of the turtle's breathing only told part of the story.

The purple-masked turtle passed him the stethoscope wordlessly, and Luke adjusted the instrument into his ears. The man was dying to know the entire explanation behind whatever trouble Raphael and Marcus had been in, but it could wait until he checked something.

A few seconds of listening to his breathing through the stethoscope revealed the intermittent popping sound that Luke hadn't wanted to hear. Inwardly the doctor cursed and felt himself paling. This is probably all my fault.

Slowly he removed the stethoscope from his ears, allowing the instrument to hang loosely around his neck. "This isn't a normal bug, Donny. I've heard this sound and seen this condition many times over the last month. I think Raph has the new strain of H1N1, and I'm likely the one who gave it to him."

Don's brow creased with confusion. "But…Doc, you were inoculated! I was the one who came down with something, even if it was nowhere near this bad. Are you sure that trauma from last night couldn't have anything to do with the edema in his lungs?"

"Donny, I know what I'm talking about where this virus is concerned. I've seen it in action and been exposed to this particular strain for weeks. Just because I had the shot doesn't mean I can't carry H1N1. You know there is a window of time that exists before antibodies kick in, enough that I could have transmitted it to you."

"If that is true, why didn't I get sick like Raph is?"

"There are many cases where people already possess some built-up immunity to the new strain of the virus, based on their flu history. Their past experience with a specific 'version' of the flu puts them at less risk for contracting the current one. I think it's possible that you suffered a milder version because of an immunity you could have built up. It's happening on the surface between other sets of siblings, with one child getting a lot sicker than the others."

"How can we know for sure?"

Luke shook his head. "We can't. The Center for Disease Control is the one who's testing for H1N1. But this 'crackle' I hear in his lungs accompanying the build-up of fluid is one of the unfortunate new hallmarks of this strain. The amount of pulmonary edema I've witnessed has a direct correlation to the rise in hospitalizations. The fact that he isn't coughing only hurts his case. The junk he's draining has nowhere to go except his lungs."

"When you called me, I was already considering oxygen support."

Luke nodded. "We should take that step now. There's little more we can do than try to address the individual symptoms. Did you even try giving Raph tetrozine?"

Donny exhaled. "Marc and I conferred on dosages last night, and started him on a few units of both hydralin and tetrozine."

"I really wish you would have called me. You said that the hydralin isn't making a dent in his fever, and I don't see the tetrozine making a difference either. Don't bother giving him any more. The focus needs to be on keeping him hydrated and clearing up his chest."

"There's the fever too," Don said softly. "I hate the thought of it going any higher."

"Don, you guys have fought fevers without medication before, and we'll do it again."

The purple-masked turtle's gaze held apprehension. "People are dying from H1N1 in the hospital, where they have all the best treatments available. Young people his age are dying."

Luke took a deep breath. Okay, time to take a step back. "Donny, why don't you sit down for a minute?"

"I've been sitting all night."

"Do it anyway."

Donatello obeyed that time, fixing Luke with a pleading look that the man wasn't sure how to interpret.

"First of all, Raphael is not on his deathbed," Luke started. "He's not in good condition, but it isn't time to panic. I'm sorry if I scared you with my opinion of his diagnosis. I'm used to being up front with you."

"Of course it makes me nervous, Doc. That doesn't mean you shouldn't have told me."

"We're going to address all the major issues and use every natural means we can come up with to combat his symptoms. We will bring his fever down, Donny."

Don swallowed. "Sooner the better. It's getting dangerous."

"We're used to danger," Luke said evenly. "And you probably need some sleep. Haven't you been up all night?"

"Yeah, but—"

"But nothing. If you don't get enough rest, your immune system is going to crash. I'm going to let you get me up to speed on how the evening started , we'll do a couple of things for Raph, and then you're going to your room for a few hours."

"Are you grounding me, Doc?"

"You can call it that if you want – I don't care. Some of your Sensei's herbal remedies may be able to help bring Raphael's fever down. Have you given any thought to that route?"

"A little…there's also a possibility that one of his old recipes could help clear up Raph's lungs too. Master Splinter used an onion poultice on us more than once as kids. It was pretty effective. The only problem with a poultice is that it needs to be applied along with heat. His fever would have to break first."

"Do you want to set up some fresh compresses for him? I'm going to start Raphael on the Oxi for now. Hopefully it will provide enough support for his respiration, and we won't have to resort to a stronger method of mechanical intervention."

Luke pondered different methods they could try to bringing Raphael's fever down while he set the bed up a little farther. He was on automatic pilot as he changed a setting on an Oxi mask and adjusted it over the older turtle's head.

Donatello's eyes were a little brighter as he returned from soaking a couple more compresses in the sink. "I never imagined the possibility of us being capable of exchanging viruses between us, Doc."

The man shrugged. "You have a lot of human DNA, Donny. Just because it isn't pure doesn't make us light-years apart genetically. I bet we're more similar than you've allowed for." Luke smiled suddenly. "If you let things work out with Jen, who knows? Maybe there could be a kid in your future."

Donatello snorted. "Don't be ridiculous, Doc."

"I know, right? It's okay. At this rate, I probably won't have any kids either."

"Doc…" Donatello's face instantly fell.

Luke thumped his shell in a friendly way. "What I'm trying to say is that my life isn't empty, no matter what. But in the future, I don't want you deciding what I need to know, or when. Something happens, and you call me. Period."

Don gave him a faint smile. "Gotcha, Doc."

"Now. I'm still very interested to hear what in the world happened with Raph and Marcus."

"Raphael got into trouble by himself. Marcus just followed him."

"I'm not following you yet, so you'd better keep talking."