Unwritten Destiny

Edgar King was living the happiest of lives. He lives in Dubai, arguably one of the best places to live in, with his brother, William King, and his closest friend, Rachel Green. He wanted nothing more out of life, except to see his two friends succeed in their careers and to succeed in his own career. What could possibly go wrong? Turns out, a lot of things could go wrong.
P.S. The diseases/events/interactions between people/effects of medications/etc. are all heavily researched and their effects were written to resemble reality as closely as possible. Many hints and clues for subtle sub-plots are also included. Pay attention to every detail, as no single word was written without a hidden meaning.