Yu Ziyuan intended to break the rule Zhao Yang made, and that's not a small matter. But would she care if she could harm Lai Jiayi? She wouldn't. And if she went back without anyone knowing, she would be safe.
Zhao Yang actually made the rule separating the guests and the non-guests to ensure there were no assassins or ill-intent people among the employees mixed with the guests.
This rule minimised the chance of anyone getting assassinated, but he didn't think someone would make use of the dark to sneak into the inner circle.
It didn't mean that he didn't station some guards around the inner circle, but would any of the guards recognise Yu Ziyuan sneaking in the dark when she could quickly blend in with the female guests?
Not all the guards were equipped with thermal-vision weapons, and even if some of them saw the woman, they would also not prevent Yu Ziyuan from entering the inner circle since they knew she was Zhao Yang's secretary.
