Inside the office, he slid a needle into my arm and drew a vial of blood out. Since I had no idea how microscopes worked, I supposed it would take a while, but he waved me behind the desk almost immediately.

"Look through that top part there," he said, pointing. "Your platelets are moving just like mine."

I peered through a glass lens with a red smear at the bottom. Little orb-like things swam across the surface. Relief brought a smile to my lips as I leaned back ...