Athena offers Jung Woo a trade, the SNC for Hye In. Jung Woo is hellbent on rescuing Hye In. Jae Hee figures out what he's up to and persuades the NTS director to let her follow him.
In the process of getting the SNC from Jung Woo, Athena kills Dr. Kim, who you initially are made to believe is Hye In.
Jung Woo, Ki Soo and Jae Hee follow Athena to the warehouse where Hye In is supposedly being held captive.
Hye In was about to escape when she hears Jung Woo inside the warehouse which is about to explode. She goes back in to save him. I thought Soo Ae's [Hye In] hair [yes, her hair] deserved an award for this scene lol.