"Matt! Stop!"

When Matt pulled the car over on the side of the freeway in Oakland beside the unconscious man with blood gushing from his face, his teeth knocked out, a massive hematoma on his forehead, his knee broken in half, and his ankle stripped of skin and askew, I noticed that he was still breathing, but his chest was rising and falling the way people with severe head trauma breathe - not normally. He still had a pulse, but it was fast and thready.