With scalpel in hand, she cut deeply across her chest. It didn’t hurt. Nothing hurt now. She reached in a trembling hand and shoved it under her ribcage, then tore out her still-beating heart. Blood dripped onto the pages, sinking crimson deep into the paper. There was only one place left for her heart. Vision fading, she placed her heart on the open book. It gave a few final beats before it became as still as the words on the page. But blood still ran, pooling in the spine and soaking through every inch of paper until words became blood and blood became words.
Disclaimer: I took this writing prompt a little too literally! But it ended up being a rather apt metaphor for how difficult writing can be at times, and how deeply writers dedicate themselves to their craft.