They knew. Everybody knew.
Somehow, caught up in an akuma attack, she had lost her earrings. Well, they fell out of her hands. She nearly gave up her miraculous to save Alya. However, when she took off her earrings, the akuma, and obviously Hawk Moth, became shocked at her identity, and let go of his hostage. She could only watch as Chat dove off to save the girl, however she noticed that her earrings were not in her hand anymore.
She spent ages looking for them. After a couple of days, to her surprise, Adrien returned them along with an apology, and a crazy new revelation. He was Chat Noir. In fact, she had no idea why she hadn't connected the dots before! Even Alya had practically told her that he was Chat!
However, her revelation wasn't as beneficial as expected. Her house was constantly bombarded with fans, so she had to stay at Adrien's most nights, because of his large security system. Not that it was a bad thing so stay at his house, but of course in a separate room on the other side of the mansion.
Though Chat's identity was still secret to the public, she was worried fans would soon find out. Plus, there was so much danger with her revelation. Hawk Moth could go after her civilian form. As he had tried to multiple times. He tried to akumatise her, but being the extremely positive person Marinette was, that became unsuccessful. That didn't mean he couldn't go after her family or friends. Or that he couln't go after her as his own civilian form.
And that's exactly what happened...
