The valve of my father’s mouth, drugged soft by medication, sips smudged moonlight from the ICU’s dark windows. My eyes blink childhood memories over the relentless blinking of the monitor’s pulse reading. The tip of my index finger trembles willing the endlessness of this relentlessness. Night after night, I find music in the elegance of sine waves coursing their choral prelude across the display. In his sleep, my father keeps trying to remove the oxygen-delivering two-pronged cannula from his nostrils. I try distracting his hands with my hands. One time in resistance, he slaps my wrist hard and the waves rush all over the screen, their curves distorted, their velocity signaling he is not yet out of danger. It seems impossible to grasp the shadowy mathematics of a heartbeat every time his hand grasps mine. Eyes closed, he tugs at the catheter, scratches the moles on his chest, pinches the sag of his chin— all the while murmuring what seems like a prayer. Listening to the shape of his mouth, it is my mother’s nickname I hear.