The shot of dye traveled from the vein in my wrist to my liver in two heart beats. Thump thump. Thump thump.

I lay on the metal table and looked up at the screen, where my liver was represented by hundreds of tiny moving dots. It looked bigger than I expected, but they are known to be large.

The machine above me, filled with geiger counters, detected the presence of radiation in my body.

I watched the dots. They moved like a hand-drawn cartoon of a liver-shaped swarm of fireflies. The dye began to move down into my gall bladder, my duodenum, my small intestine. It drew the outline of my guts on the screen. A nebula of stars, shaped like organs, on a black sky.

One hour passed. The doctor passed something from the IV into my body: a synthetic hormone which mimics a signal from the pancreas. Within thirty seconds I was nauseous. Within three minutes my stomach was doing backflips. He stopped the drip and told me I’d get better in a couple minutes. Sure enough, I did. Mostly.

We waited for my gall bladder to drain. It looked like a little golf ball above my intestine. My liver was dark again — having expunged the dye. I stared at the screen, only twenty minutes left. It didn’t change much. It began to look like a drawing of a woman in a dress, maybe standing at a butter churn, with my gall bladder as the scarf on her head.

When it was over, I put my shoes and sweater back on. I went to the car and drank water, then drove to the store to buy muffins and orange juice. I wondered if later on my body will produce anything that glows in the dark.