In her panic state of wanting to get away, she asked for the door. She didn't have a destination where she wanted to be. The first two times when it worked because Hue Chi was her destination and she visualized him in her mind, so no matter where he is, the energy will take her to him.
Not sure if her conclusion was 100% correct, she thought of her room in the cruise. Poof! She saw the door only visible to her. She walked through the door and travelled through the space and through another door to her room. The door was now more solid than it was the first couple times.
To Hue Chi, it looked like she took a step and faded into nothingness.
Yu Sha arrived in her room and understood that she missed something that seemed so obvious. She sighed. "Damn... I owed him a thank you."
'If he didn't break down those questions to me, I would still be wrecking my brain.'