Complex sentence: Rocks learns Dr. Clitterhouse's real name and shows up at his Park Avenue office one day and tries to blackmail him into continuing his leadership of the gang's activities, as Rocks recognizes his talents, but wishes to keep all the profits and power for himself.
Split into simpler sentences: Rocks learns Dr. Clitterhouse's real name and shows up at his Park Avenue office one day. Rocks tries to blackmail the doctor into continuing his leadership of the gang, as Rocks recognizes his talents, but wishes to keep all the profits and power for himself.