Kreizler (Daniel Brühl) and Sara (Dakota Fanning) discuss the capacity to kill. Moore (Luke Evans) goes on a date. Byrnes (Ted Levine) and Captain Connor (David Wilmot) keep an eye on a potential suspect. Roosevelt (Brian Geraghty) finds himself under public scrutiny. 
- Lincoln Steffens: "Is it true that the dead boy was dressed as a girl, Commissioner Rosevelt?!"
- Dr. Kreizler (to John Moore): "What we are missing, John, is not how he kills, but why and most importantly, when will he kill again?"
- The episode covers from Chapter Sixteen to Chapter Twenty of Part II of Caleb Carr's novel, with several changes and additions of few original scenes.
- The letter sent to Mrs. Santorelli by the killer is based on the letter that serial killer Albert Fish sent to his victim's mother. Fish was a child rapist and cannibal active in New York and neighbouring states between 1890 and 1930.