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. Our newest podcast, “The Preventionist” is out now. Search for it wherever you get your podcasts. To get full access to this and other Serial Productions and New York Times podcasts on Apple Podcasts and Spotify, subscribe at nytimes.com/podcasts. 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