The answer to this question is: Leave/ will arrive.
Answer:
no I do no think it contains a comma splice
It is dark because Barnardo has trouble seeing the other guard.
This scene takes place at midnight and it is so dark Barnardo cannot see the other guard. Barnardo shows up for his shift, but he can't clearly make out who Francisco is. Francisco has the same problem because instead of answering Barnardo he tells him to identify himself first. They get it figured out and Barnardo begins his shift.
To soften his later attacks that the United States was indifferent to the suffering of the Jews.