Nurse Kayla can't stop thinking about the day she listened to the Doctor's heartbeat! He was feeling stressed and overwhelmed by work and his racing pulse was worrying him a bit. Kayla knew that all he was wanting was someone to vent to, someone to give him some reassurance that he was okay. And she was happy to do that! Hearing his pounding heart in her ears for the first time, Kayla began to think and feel things she had never felt before! Now, all of her thoughts, all of her days, are consumed by the idea of the Doctor and her listening to each other's heartbeats together! But how can Kayla ever find a way to make that happen? Won't the Doctor think she is weird if she tells him about her secret heartbeat fetish? Nurse Kayla decides to leave an anonymous, and slightly unusual, love letter on the Doctor's computer desktop. She records her heartbeat for him! Kayla lets the Doctor hear her heart at its slow, steady thump and then increases the intensity by letting her hands run all over her body, making her pulse start to pick up. She edges herself closer and closer to an orgasm, over and over again, recording the picking up and slowing down of her heart as she plays. As quietly and sneakily as she can, Kayla has an orgasm in the Doctor's office, letting her pounding heart be the only noise in the room. She quickly saves the audio file and hopes that the Doctor will enjoy her  secret "love letter" and begin his search for the sender!