It's Them Again Metaphors
From text I can assume that the night men were the people that burned the Berry's. For example, on page 62, it states "You know what some of 'em done to the Berry's." This shows that the men riding that night maybe the people who burn the Berry's and are out to do so again. Those men riding are out to get the people who ruined the bus for the white kids. Another example, is stated on page 60, "It's...it's them again, they's ridin' t'night." Mr. Morrison states in that quote "it's them again" , by this quote we can predict it is someone they know and it not good. The words "it's them again" made Mama pale and frightened by the sound of the words. That means Mama must have encountered the night men before. This concludes that later in the book