Patients at a fertility clinic experience excruciating, unexpected pain. For months the reason for that pain remains hidden. Then they get a letter from the clinic. Subscribe today at nytimes.com/podcasts or on Apple Podcasts and Spotify. You can also subscribe via your favorite podcast app here https://www.nytimes.com/activate-access/audio?source=podcatcher. For more podcasts and narrated articles, download The New York Times app at nytimes.com/app.To find out about new shows from Serial Productions, and get a look behind the scenes, sign up for our newsletter at nytimes.com/serialnewsletter.Have a story pitch, a tip, or feedback on our shows? Email us at serialshows@nytimes.com