Sadie continues to read Bruno’s emails, and as she does so, she learns more about the Neanderthals, Homo erectus, Homo habilis, and Homo sapiens. In one of the emails, Bruno details a recently discovered skull that had features from both Homo erectus and the Neanderthals. This, he argues, proves that the species comingled and that evolution happened in fits and starts. There is much, he writes, that we do not yet understand about the history of the planet.

Sadie wakes up to a text from Vito. The two exchange a series of messages while she sets up her new router. It is much stronger than her old one, and she hopes to spend some time that morning figuring out where exactly Bruno lives. She knows that his property is in a rural area and contains an old, converted barn. Years ago, one of his children died there in a tragic accident, and afterward, his wife and the remaining two children moved away. Now grown, the surviving children seem to be living with Bruno. The property also contains a vast network of caves, which Bruno has spent years exploring. He laments that humans no longer live in caves.