What happens at the Orpheum Theater in the novel, Thunderhead (Arc of a Scythe)?

At the Orpheum Theater, Citra gleans a man according to his wishes: stabbing him during a performance of the final scene in Shakespeare’s Julius Caesar. Purity and her unsavory cohorts plan an attack against Citra and Scythe Curie during this performance. They create a fire in the theater and then taint the sprinkler supply with acid. Greyson risks his life to prevent this attack.