Chess

My dreadful situation forced me … to try splitting myself into a Black self and a White self, to keep from being crushed by the terrible void around me

A prisoner of the Nazis for years, what if your only stimulation was imagining games of chess against yourself, second-guessing your increasingly obsessed and divided brain? Then, decades later, you can play the World Champion, but might it return you to the edge of madness … and tip you over?