По тонкому льду 1 сезон 6 серия — Эпизод 6

A violent attack on Eun-soo takes a horrifying turn when she recognizes one of the masked men as her co-worker, Dong-hyun. She and Lee Kyung manage to subdue him and his brother, but their desperate solution quickly unravels when the captives vanish without a trace. Now they know who she is.