Heo Im is an oriental doctor, acknowledged as the best in acupuncture and moxibustion in Joseon. His success is blocked due to his low status.
Things can get really muddy when talking about the science of acupuncture, although this is a fantasy but to try and push one narrative over the other this desperately is a tough sell in this scenario. I don't think the drama managed to navigate mixed medicine practices from a modern medicine point of view successfully. In fact, the entire thing was dropped very quickly a few episodes later without being brought up again. So why did they ever bother? The first 5 episodes were enjoyable without overbearing time-travel cliches. However, everything turned to worse with episode 6, that's where they introduced your typical mundane cheese of someone who traveled in time. At this exact point, there was a harsh shift in the story, everything slowed down, and a plethora of extreme suspension of disbelief elements in contrast to the world building they had established were thrown in. Although we got brief hints of the story at the beginning from her grandpa and that one prisoner but it felt like it won't address these points until the last few episodes and that turned out to be true. Although I enjoyed the first 5 episodes but the rest were just disappointing.