Thanatophobia.The episode starts with a pair of boys play-fighting, while another claps to mimic the sound of heavy punches. That boy later flicks a pebble into the path of one of the border turrets, activating it and watching the resulting spectacle. Trevor Goodchild is being pressured by the government into making the border more intimidating, despite his want to make people stay in Bregna through the 'power of ideas'. To this end, he secretly allows Æon to come in and bomb the factory where the parts for the wall are being made. In a parallel and intertwined storyline, two Breen lovers, Onan and Sybil, seek to escape from Bregna into Monica through a gap in the frontier. The escape is almost a success, but one of the turrets shoots Sybil in the back, destroying one of her vertebrae. Now she can only stand up straight when a special ampoule is inserted, though when she takes it out she has otherwise impossible flexibility, making crossing successfully a stronger possibility. When she is forced to work in the factory being bombed by Æon to pay off her medical bill, Trevor takes an interest in Sybil and visits her in the guise of a doctor, manipulating her nerves through the gap in her spine to stimulate orgasm. Jealous, Æon indulges Onan in his sexual fetishes while he visits her to find another way of getting his lover across. Eventually, Sybil finds out and angrily refuses Æon's offer of help, telling Goodchild about Æon's secret way into Bregna, and finding out about his resistance to the new border defenses. Trapping a returned Onan in her apartment, Sybil attempts the border crossing again. This time, she avoids the turrets, but before she can pass through the small entrance into Monica, wires trap her legs and robots built with the parts she has been helping to manufacture anesthetize and amputate them, leaving her trapped in Bregna forever. The episode ends with the boys from the beginning fighting each other for real, with the clapping boy sitting nearby, though now his arms are missing, showing that he had tried his stone trick again and been caught by the robots.