Initially, Nora had thought that even though it was obvious that Ruth was making things difficult for her, she was indeed acting according to regulations.
After interrogating the suspects and finding out that the mysterious organization's ultimate mastermind was Yvette, she should indeed interrogate Nora.
But Nora was not just anybody. She was internal personnel of the special department.
Even if they wanted to interrogate her, they should have asked Morris for permission first. After all, she was someone whom Morris had specially recruited!
When Ruth detained her and forbade her from leaving, she could understand and think of it as Ruth trying to prevent her from taking the opportunity to escape in case she really was involved with the mysterious organization.
Therefore, she had intended to cooperate with them in the beginning.
After all, once Morris returned, the truth would come to light.