In the book Chains, there is always a quote that precedes each chapter. How does the quote that precedes Chapter 43 connect to the chapter?

The quote at the beginning of chapter 43 of Chains is this:

"That even in Failure cannot be more fatal than to remain in our present Situation in short some Enterprize must be undertaken in our present Circumstances or we must give up the Cause... our affairs are hastening fast to Ruin if we do not retrieve them by some happy Event. Delay with us is now equal to a total Defeat." 
-Colonel Reed to Washington

Throughout the novel, Anderson has been comparing the United States' struggle for independence to the struggle of Isabel for freedom from slavery. This quote is no exception. Colonel Reed's argument to Washington in the quote is that the situation for the rebel army has become unbearable and, if they ever hope to gain victory, they must take action to change their current circumstances. Up until this chapter, Isabel has been waiting on other people (specifically the rebel army and Curzon) to take action that will hopefully lead to her freedom. In this chapter, though, she is put in a dangerous position: her owner, Madam Lockton knows that she is carrying notes for the rebel army and demands to see one in particular. She threatens Isabel and even threatens her sister, Ruth, who Isabel thought had been sold. This threat also provides a glimmer of hope: Isabel sees that she could escape and save her family after all, but only if she acts right away. Like Colonel Reed, she knows that immediate action is necessary to survive and that present conditions are unbearable.