The scent of blood was the first thing Mello noticed when he opened the door, though he processed it with the same detachment he'd feel for the smell of sweat or mold. Although he'd only been in the hallway for a few seconds, the bright light made him blink, and when he scanned the room he saw more than enough blood to justify the overpowering smell. There were a lot of people crowded into the small space, most of them uninjured, but it was possible that none of them knew what they were doing. While his knowledge of medicine and anatomy was more theory than practice, traumatic injury had been especially important in forensics and criminal investigation. In other words, he'd worked damn hard to learn it, and it wasn't going anywhere anytime soon.

Mello had always assumed that his best qualities were innate: speed of thought, deductive skill, and the ability to think on his feet. Active intelligence. Kinetic intelligence. Factual knowledge was like ammo, and although it was smart to keep a large supply at hand, all the bullets in the world wouldn't help you if you didn't know how to aim. He couldn't remember the last time he'd drawn on this much textbook information in one day, but he had a feeling he'd been using a number two pencil.

Those all-nighters were finally paying off with something more than frustration and homicidal fantasies.

"Tamaki?" Mello said as he stepped in and nudged the door shut with his foot. "I figured you might be shorthanded, and I know a lot about this kind of stuff. Anything I can do to help?" With luck, he'd be able to make himself useful before asking to borrow a scalpel, but if not, he'd repay his debt the following night. He didn't want to gain a reputation as a freeloader, but Tamaki had seemed nice enough at breakfast.