Battle for Happiness S01 E15 Episode 15

"She died for someone's happiness."

Ji-ye clams up upon Do-jun’s threat. Mi-ho and Do-jun are out to find the black USB before one another. While trying to replay what happened the night Yu-jin died, Mi-ho realizes where the USB might be and finally finds it. The USB contains audio files of Yu-jin hiring a hitman on Do-jun and him doing the same. Mi-ho is sure that Do-jun is the killer, and he kidnaps and takes her to his clinic.