The laboratory was unusually quiet as Foreman and Chase waited on the results of their latest tests. They'd sent one sample off for a frozen section tissue biopsy, hoping it would buy them a little more time to examine the others.

"Low iron, low blood calcium... Foreman, you're not going to believe this." Chase sighed, falling back in his chair.

"What'd we miss?"

"Actually, we didn't miss anything." Chase handed him the paper.

"Leukocytosis. White blood cell count is slightly elevated, just like the first time." Foreman read quietly. "I guess House was wrong about you making a mistake."

"No, I was just wrong about what mistake you made."

The door to the lab swung open, and House limped inside. He held the film from the MRA against the light, studying it again.

"The answer was thromboembolism all along."

Chase stood up, snatching the film from House's hands.

"We've looked a thousand times, there is no clot."

"Did I raise you to only think inside the box?" House struck Chase on the side of the thigh with his cane. The reaction was instantaneous. His face soured, as if his stomach had just dropped into his knees. Pain spread up the leg, and Chase had to brace himself against the lab table to keep from falling to the ground.

Foreman paused.

On one hand, that strike could have been a vital clue. House could have been hinting that the numbness was the result of thromboses blocking the tiny vessels that fed the nerves. It would have been undetectable in their test. On the other hand, he may have just done it for fun.

"What… what was that for?" Chase finally exclaimed. House answered with only a smile.

Unfortunately for Foreman, the grin usually meant it was the latter.

"You don't see anything unusual?"

Foreman held it to the light and studied it again.

"No. I don't, House. The blood vessels are fine."

"Do I need to hit you too?" House groaned.

"I don't see a clot!" Foreman repeated. "I don't see one because there isn't one! And if there isn't a clot, it means the answer isn't thromboembolism!"

"Exactly!" House interrupted. "The answer isn't thromboembolism!"

"I thought you just said that it was!" Chase shouted back, rubbing his sore leg.

"It was!" House returned, even louder. "But not anymore. Until now, we've been assuming his first exposure to heparin was a mistake. That's where we made a mistake. Now, assume that it wasn't, and that he was treated for the thromboembolism, successfully, I might add, before he was ever brought here."

"That would mean there's another underlying condition, maybe an infection of some kind, that everyone missed."

"House, the blood work doesn't fit." Chase protested. "And I didn't make a mistake, it's the same as before. Neutrophilia isn't high enough to indicate a bacterial infection. And Lymphocytes are far too low to indicate a viral one."

House shuffled closer, and took the report from Chase. He bit his lip as he studied the numbers. Foreman, meanwhile, had turned his full attention to the MRA film.

"Neutrophils should have increased following the heart attack caused by the heparin…" he whispered. "That's unusual..."

"House, there's gas in subcutaneous fascial planes..."

The three shinobi exchanged glances.

"Necrotizing fasciitis." Chase answered after an uneasy pause.

"Could be the result of an underlying clostridial infection." Foreman added.

"Maybe, maybe not." House replied. "Could be any number of different bacteria. Analysis of the discharge from the patient's wounds will narrow down source of the infection. In the meantime, treat for everything. Looks like he's imm…"

"He's immunocompromised!"

Dr. Cameron skidded to a stop, just inches away from the table. The chakra in her feet burst like a shock wave, sending her hair flying and her lab coat billowing. The papers sitting on the table met a similar fate, as Foreman tried his best to catch them and shove them back in their proper order.

House, meanwhile, was far more interested in Cameron.

Her appearance was oddly disheveled. Her breath came in sudden, ragged gasps. Sweat clung to her skin in such a way that her breasts could almost be seen through her shirt. But for once, that wasn't what he was looking at. A mad sprint from the intensive care wing to the labs shouldn't have been taxing enough to literally take her breath away. House knew that. She must have been moving faster than even her own chakra would allow. And yet, he could sense it still radiating wildly throughout her body in a manner he hadn't heard of since... House gasped.

"How do you know he's immunocompromised?" he immediately asked. His voice was stern, almost shrewd.

"Because his body…" Cameron started to explain, but suddenly stopped. She fell to her knees, clutching her neck and her sentence ended in a fierce scream.