She blinked slowly. "That's... That's my job. That's what I do. I deliver oxygen and nutrients, and I return the waste. I mean, I've helped with healing before, but that's more because of the platelets and their clotting factors and their fibrin. When that happens we kind of get stuck--" She lifted a hand, self-consciously scratching at the back of her neck. "Any blood cells close by get stuck at that point, until everything's pulled back together. Even the white blood cells."