-( Spoilers ahead, be warned now )-
By following Flora into Chapter 0, we discover the final piece of the puzzle (and another puzzle starting all together). Flora, from the future, arrived using the machine from the basement and questions Tesla as to why the machine didn't work. When told he will never tell her and that the only way to get in to the mansion is by killing him, she realizes that the moment in time has come full circle, having been the one that killed him.