The clinic was clean but cold, especially for the plasma donors. As they sat for an hour, blood was pumped from their arms into a centrifuge machine that spun their yellow, protein-rich plasma away from the heavier red blood cells. The plasma would be bagged, tagged, and flash-frozen, while remaining blood cells — now room-temperature, colder than when they left — were pumped back into their body, along with a chemical coagulant to prevent clotting. An impossible-to-ignore odor permeated the building — a mix of the iron-rich scent of blood and the acrid smell of the chemical. Unlike donating blood, when you donate plasma, your blood is returned to you — you get something back. But it’s a little different: colder, and a touch unnatural. And the process can wear on the body. Repeat donors have learned to bring their own blankets.

Kathleen McLaughlin was interviewing for a job. This plasma clinic was in need of another phlebotomist, someone to help administer the roughly 1,200 donations that came in weekly. Only McLaughlin didn’t have any medical training. She’s a journalist who was finally getting a behind-the-scenes tour of a plasma clinic for her book Blood Money: The Story of Life, Death, and Profit Inside America’s Blood Industry, published earlier this year, asking nonstop questions and hoping she wouldn’t be found out.

Ultimately, her medical background wasn’t that important. Instead, the managers were more interested in her customer service experience. Having a steady hand to puncture a vein is important, but a bedside manner is perhaps more so when your industry depends on new and returning customers to fill the clinic’s recliners seven days a week.