A Shot against Post-Traumatic Stress Disorder

Each night before "Greg" goes to bed he brushes and flosses his teeth. Then he double-checks the instructions on the dark brown bottle his nurse gave him before he unscrews the cap and tips five drops of a light-amber, oily liquid onto a spoon. The brew, glistening from the light of the bathroom fixture, is tasteless and has no odor he can detect. But it's chock-full of bacteria.

He sloshes the substance around in his mouth and swallows.