The "Part 33" in the title is the section the New York Supreme Court building where the trial occurs. This episode is mainly confined to the courthouse.
Carisi brings up two incidents from Fin and Rollins's past, which include Fin traveling to Cuba to pick up Byron Marks in the episode Gone Fishin' (2017) and Rollins bonding with Esther Labott in the episode The Book of Esther (2018). Benson also talks with Rollins about her experience with William Lewis from the episode Surrender Benson (2013).