What does Winter learn about Midnight through the letters she stole from Sister Souljah?

Through the letters Winter stole from Sister Soujah, she learns of Midnight, or Bidal's, background. He was born in the Sudan but came to America with his pregnant mother at age seven, following the murder of his father. As a teenager, he spent five years in prison for killing a man who attempted to rape his little sister. Shortly after his release, his mother died, and he discovered that Efe, his little sister, had been adopted by a white family. He was taken in by Ricky Santiaga, so he owed Santiaga loyalty. Souljah refused to have a relationship with him because he was involved in drugs.