David and the other members of the group receive a compelling call from Petra, who has ridden a pony into the sometimes-dangerous forest that separates Waknuk from the Fringes. While not as strong as her call when she fell into the water, this summons still carries with it so much feeling that it blocks the group’s communication channels. Consequently, David has no way of telling the others that he will go after Petra and that they needn’t heed her call.
Once again, the strength of Petra’s ability endangers the lives of everyone else in the group. This incident is in sharp contrast with Anne’s suicide. While Petra exposes the group unknowingly, Anne does so with the full knowledge of what will happen if the group is discovered.
David rides his horse into the forest until he reaches Petra, whose pony is being attacked by a mutated cat. Rosalind and Michael, who have also rushed to her aid, shoot the animal with arrows and then try to comfort Petra before the others respond to her call. Petra has no idea that she is emitting this signal, however, so they struggle to calm her down. Before they are able to do so, most of the group arrives in the forest. Michael is able to get away, but a stranger arrives at the scene before Sally, Katherine, David, and Rosalind can separate. The stranger questions them about how they could have all known Petra was in distress. Katherine and Sally say that they heard Petra and her pony screaming, but the stranger responds that he was right behind them and heard nothing. The man does not seem to believe their story.
The attack on Petra’s pony by a mutated animal can be read as symbolic of the destruction of Petra’s innocence and freedom by a monstrous society. While the pony is proof to the stranger that Petra truly was in danger, he seems much more concerned with figuring out how the group knew to find her than with her safety and well-being.
David takes Petra home and the group discusses what to do about the stranger who saw them, now identified as Jerome Skinner. Michael tells the others that people have an idea that “telepathy” might be possible. He says there’s a chance that think-together might not be considered an Offense because God has the ability to see into people’s minds, and thus it would be in his image to be able to do the same. The group decides that they can never meet in person again, and that if Petra emits another call, everyone but David and Rosalind will do their best to ignore it.
Despite the fact that the group has something legitimate to fear, they stay as calm and rational as possible and do not rush to action. Wyndham contrasts this fear with the fear of the unknown that might motivate Skinner to report them. This juxtaposition makes it seem especially absurd that a grown man would be willing to endanger the lives of multiple people simply because he isn’t sure how they learned their friend was in danger.
David talks to Petra about thought-shapes and tries to teach her to control them. She struggles to moderate their intensity, but makes progress over time. Petra complains to David about the difficulty of understanding what the far away voices are saying. David thinks she is referring to Katherine and Sally, but it soon becomes clear that Petra has a much larger range than anyone else, and, as a result, can hear voices that no one else in the group can access.
For the first time, the group learns that Petra’s powers go both ways. Not only can she send thought-images in a way that no one else can, but she can also receive them. With this realization the group learns that they might not be entirely alone in the world.
A few days later, Uncle Axel tells David that a friend of the Inspector has been asking about him and Rosalind. He suspects that Petra might be to blame. David is shocked because he hasn’t told Uncle Axel about Petra, but Uncle Axel explains that before she died, Anne told Alan about everyone in the group. When Uncle Axel figured this out, he shot and killed Alan to prevent him from talking. He cannot figure out, however, how to account for the recent questions about David if Alan was killed weeks ago. David tells him about Jerome Skinner and the events with Petra’s pony. Michael realizes that Skinner only saw Petra, Rosalind, David, Sally, and Katherine, so the other members of the group are still in the clear. The group decides to start preparing so that everyone can escape quickly if necessary.
Instead of convincing the group to kill Anne, Uncle Axel went ahead and killed Alan instead. His willingness to kill to protect his family is entirely different from Joseph Strorm’s willingness to kill his family to protect his beliefs. Michael realizes that the fact that their deviation does not manifest itself physically is a great advantage, and means that some of them are not yet in danger.