Summary

Pearl notes Stasha's growing distance. She is always taking notes in her “medical diary” and examining Patient Number Blue (70). Stasha confesses her immortality guilt, but Pearl thinks she is just making things up. She does, however, believe in her sister's sincerity in regards to killing Mengele and freeing the Zoo, and it scares her.

Patient Number Blue explains that he must persevere and have a life worthy of his dead brother's sacrifice. He and Stasha bond over their mutual plans to kill Mengele. Pearl reflects on the fact that Patient Number Blue's time is limited, once a twin is no longer a twin, he ceases to be useful for Mengele's experiments.

Back at the lab, the twins are separated, and Pearl knows that they are pouring scalding water into Stasha's ear in the other room because she can feel...