James was in on it
Adrian and Tom bribed James with money for Sydney's college fund, and he was the spy that kept tabs on Cecilia. It's why he's vaguely patronizing throughout the film, because he doesn't really care, and why he tries to convince Cecilia to not go after Adrian after Tom is caught because he's worried if Adrian is caught the money will disappear. Cecilia figures it out and ropes him into to being an accessory to Adrian's murder so he'll never rat on her. Cecilia will become an anti-hero called The Invisible Woman
This is a disguised sequel for the Dark Universe. There will be a movie where all of the monsters will be summoned to battle a bigger threat. There will be an Avengers like team (but with horror monsters), and Cecilia will be a member.- And another member if this hero league is R.M Renfield.
Adrian filmed everything he did to Cecilia.
Since the suit was covered in cameras, he also had them record his stalking of Cecilia and his brothers actions. His murder will be stored away on his computer. After the events of the movie, a man named Skinner got his hands on the invisibility suit and joined The League of Extraordinary Gentlemen.
