Complex sentence: Since working as a consultant with the SI branch is his main source of income, Dresden hurries to the scene of the crime--a room at the Madison Hotel, hoping to make it back for his appointment with Monica.
Split into simpler sentences: Since working as a consultant with the SI branch is his main source of income, Dresden hurries to the scene of the crime--a room at the Madison Hotel. He hopes to make it back for his appointment with Monica.