"Are you seriously trying to kill yourself?" Simon asked wearily. "Because that's what's going to happen if you keep doing these things before your body is ready—"

"It ain't up for discussion, Doc," Mal said, buckling on his holster as he slowly descended the stairs to the cargo bay where Zoe was waiting.

"Nothing ever is with you," the younger man said half to himself, following on the captain’s heels.

Mal paused when he reached the floor, turning to face Simon with an accusing look. "He's the only one's got any idea what it was he stuck Inara with. You say knowin' can help her; I aim to find out. Might have thought of that your own self before now.”

Simon's mouth fell open in incredulous indignation, unable to believe that Mal could say that, after everything he had done to save both his and Inara's lives; the endless hours of surgery without sleep, working blind to fight the unknown agent that was attacking Inara’s heart… Overwhelmed, he had a sudden urge to strike Mal, the feeling so strong that his hands actually curled into fists, his face darkening with a thunderous fury.

Mal blinked and then tensed, readying to defend himself from the deadly intent he saw in the younger man's eyes, but then Simon seemed to catch himself, forcing his fingers to relax w