What is a central idea that the author develops throughout the dark game?

The central theme about the Dark Game was dangerous it was to be a spy.  Elizabeth took many risks in gathering and sending information to the Union lines.  She also took care to help Union escapees get back to their troops.  It was dangerous but she firmly believed in preserving the Union and took the risk to all of this.

this answer was editing it cause i couldn't delete!

a. it reminds protestors of the reasons they have to protest.