In love, engaged, dead

A young student falls to her death on the day of her engagement in her wealthy father's penthouse. Was it an accident, or a cold-blooded murder? You slip into the roles of retired detectives. Herbert Kogler, an old acquaintance of yours, has lost his only daughter. He is the owner of the largest and richest real estate company in the city. Whole districts in the city center are exclusively real estate in his possession. This includes a luxurious, two-story penthouse where his daughter wanted to celebrate her engagement to her great love with friends on the day of her death. In the middle of the night, she fell down the stairs and landed with serious consequences. She was killed instantly. Herbert Kogler has commissioned you to shed some light on the matter alongside the police. Of course, you want to comply with this wish - even though you know it will be anything but easy. You are retired, so technically you are not allowed to officially investigate. If you want to get hold of specialists' reports, you will therefore have to pull some strings.