One the Woman Season 1 Episode 16
Mr. Double Agent
It is too late when Yeon Ju realizes Hak Tae switched his side to Sung Hye's, and her team fails to arrest Sung Hye at her inauguration. Yeon Ju is confused and upset with Hak Tae and decides to meet him personally, but he secretly puts something in her drink. Meanwhile, Mi Na wakes up and visits her in-laws to reveal Sung Hye's most brutal crime of all.