Haunted ( Lockwood and Co )

Anthony Lockwood and Yasmin Brooks were best friends since they were kids. Yasmin had talents such as sight, touch, listening, and talking with the dead even if they weren't a type-3. Lockwood and Yas always went out into cemeteries and haunted buildings and homes to see what kind of trouble they could get into.

One day they took it too far.
Lockwood and Yas went into the wrong house and Yas saw things no child should see. She had already had a bad feeling when she and Lockwood entered the property but Lockwood wouldn't listen. She had begged Lockwood for them to leave but they got separated and she found herself in the basement locked in with a full-body mirror made with human bones and blood and a type-4 ghost who happened to be a sadistic psychopath when he was alive and showed Yas what he did and told her the same thing was going to happen to her, She saw horrible things in that mirror and the walls started to bleed making her think she was going to drown in the blood causing her to scream as loud as possible so that anyone could help her. Lockwood had no choice but to call DEPRAC for help. By the time they found Yasmin, she was covered in blood and was screaming at the mirror begging for it to stop.

She wasn't the same after that and she begged DEPRAC to destroy the mirror but they didn't listen and wanted to do experiments on the mirror, Yasmin was sent to move to America as she was traumatized and went to live with her mother.

8 years later she moves back to London to see what it has become and decides to go to Lockwoods house for old time's sake. Only to find out that he now has an agency and that the mirror that had shown her so many horrible things to her was missing and whoever had it there intended to release the sadistic ghost.