Offend him

After Lee Soohyun had the conversation with Hwang Hyunae about going to a place with more privacy provided, Soohyun had excused herself in order to go to Minhyun. She then told him about how Hyunae was suspicious and for him to keep an eye on them.

As Lee Soohyun had expected, Hwang Hyunae tried to harm her. Lee Soohyun had seen the sharp needle in her hand and realized that Hyunae attempted to harm her with that.

Han Minhyun pulled the needle out from Hyunae's hand, and his eyes scanned it, trying to figure it out. His gloved hand touched the surface of the needle, and removing his hand, Minhyun saw that his white glove was stained with beige. 

Seeing that, Lee Soohyun's eyes widened. Hyunae was trying to poison her. Although Soohyun knew that Hyunae wanted to harm her, she did not think Hyunae would want to go as far as to kill her.