In Qingjiang Municipal Hospital, where disinfectant mingles with turpentine, down-and-out illustrator Lin Xiaoman clutches her mother's diagnosis of kidney failure and dips her last sketching pen into iodine. When she disguises herself as a medical escort and slips into the cardiothoracic surgery department, the wheels of fate catch on a bloody secret from twenty years ago: the inexplicable disappearance of her father from the construction site's emergency room is closely connected to the death of the father of Cheng Shubai, the cardiothoracic department's leading surgeon.
A medical dispute during a rainstorm tears the scabs from two lonely souls. Wearing hearing aids, he leans in to listen to the heartbeat she draws with her brush. She clutches the bloodstained belt of his white coat and holds her breath, hiding in the CT room. When Cheng Shubai discovers that Lin Xiaoman can pinpoint surgical risk areas with precision by tracing the paths of patients' veins, and Lin Xiaoman notices that whenever his PTSD flares up, his pen unconsciously draws spirals, the redemption that began with a lie is being rewritten into a wild love song that brings them together.
Beneath the ultraviolet lights of the morgue, an old construction-materials test report reveals her father's employee ID number. Tucked inside the old medical records Cheng's father treasured is a ginkgo-leaf specimen from one of her childhood drawings. When a medical group threatens to silence her by holding her mother's kidney transplant hostage, Lin Xiaoman grips a scalpel concealing a tiny camera and reveals evidence of the crime from twenty years ago during a live-streamed operation led by Cheng Shubai. At that very moment, what comes through the hearing aid behind his ear isn't static, but her trembling rendition of “Heartbeat Concerto”, the rhythm of life he secretly recorded as he used the reflection in an endoscope to touch up her makeup.
A scalpel can cut open the truth, but it cannot cut off love as it takes root and grows. When Lin Xiaoman uses a medical marker to draw a complete heart on his bare back
