Not Me

When his twin Black is was viciously attacked and subsequently left hospitalised, White is was unable to endure the harm done to his brother in silence. Knowing from his brother's mouth that it was one of Black's closest friends who betrayed him, White will disguises himself as Black to root out the traitor. Was it Sean who's so calm, serious and hard to read? Cheerful and friendly Graham? Or might it have been hot-blooded Yok who likes to fight?