Six weeks later, Kerans is abruptly awoken by loud sounds outside his window at the Ritz. He steps onto the balcony to see a white hydroplane speeding around the lagoon, disturbing the water and the spiders. It's piloted by a man dressed all in white who seems to be having a grand time. Kerans hears signal gunshots, and the man steers the plane into the next lagoon. Kerans is disconcerted by the appearance of the visitor in the lagoon, as he's spent the last six weeks mostly alone in the hotel. Temperatures at noon are now 130 degrees and don't subside until Kerans is ready to return to bed in the late afternoon.
After six weeks, Kerans's prediction is proving correct: it seems as though Kerans has spent much of the time alone. This is a result of the dreams and of the process of their neuronic journeys backwards through time, which are deeply private psychological experiences. The external environment is still changing and heating rapidly, which suggests that London will soon be inhospitable to human life.
Outside, the plant life is taking over the buildings now that Riggs and his crew aren't around to cut it back. Silt accumulates in the small waterways surrounding the lagoon, and Kerans spends his days following his dreams, all of which center around a lagoon. He wants to reach the end of his descent through time, but he knows that when he reaches the end, the real world will be unbearable. Bodkin and Beatrice seem similarly wrapped up in their own private dream worlds. Bodkin is entirely lost in his mind and spends his days paddling around looking for places he remembers from his childhood. Beatrice and Kerans, however, seem to "understand their symbolic roles" and aren't as estranged from each other.
The "symbolic roles" point back to Kerans's earlier comment about the last Adam and Eve on earth, roles that he's now mentally giving to himself and to Beatrice. In that situation, Bodkin is truly superfluous, which explains why he's been even more distant. However, Bodkin's neuronic journey is complicated by his memories of the more recent past. The memories are, notably, memories of Bodkin's major growth period in childhood, which ties in with the fact that he's in a similar transformational period right now.
Kerans sees more signal shells over the far lagoon where Beatrice's apartment is, and then more from further off. Kerans understands that the hydroplane is a scout vehicle, and there are likely more groups of invaders. He dresses, goes downstairs, and steers his catamaran into the water. When he reaches Beatrice's lagoon, the hydroplane is circling by an inlet. Kerans berths the catamaran and climbs onto a department store to watch. Kerans begins to notice a sound like low animal roar drawing nearer, as well as the sounds of engines. Suddenly, boats like the one that Riggs drove burst through a dam and into the lagoon. They're all manned entirely by black men.
These invaders seem organized: they're still organizing themselves to exist together in this new world, not isolating themselves to accept the changing world like Kerans and Beatrice are. This suggests that the invaders have no intention of giving in to their own neuronic odysseys and instead, are prepared to fight nature for their place in the world. Their use of motorized speedboats shows their dominance over the natural world.
Kerans notices that hundreds of massive alligators accompany the boats. They arrange themselves around the hydroplane, where the pilot gazes at the alligators. The pilot motions to his crew to anchor in the lagoon as the alligators swim in a clockwise spiral around the hydroplane. There are at least 2,000 alligators. Suddenly, the pilot shouts and starts the hydroplane, which moves off across the writhing alligator bodies to a creek that leads to the next lagoon. The alligators follow, though Kerans can see that some were killed by the hydroplane's quick departure.
The invaders aren't just fighting nature, they're actively taming it as evidenced by their following of alligators. For Kerans, this is especially disturbing as it shows that humans are capable of changing nature and of using it for their own means. Alligators as a symbol are powerful and exceptionally dangerous creatures, and controlling those animals in particular suggests that these people know something about nature that Kerans doesn't.
Kerans rushes down the building's fire escape to the catamaran, but finds that the churning water has unmoored it. He watches as the alligators notice it and destroy it. A caiman notices Kerans in the water and heads towards him. Kerans runs back to the fire escape and narrowly escapes the caiman. He throws a brick at it and it returns to the group. Kerans spends the next half hour fighting iguanas as he crosses the 200 yards to Beatrice's apartment.
Alligators are part of the same zoological class as the iguanas; they're both lizards. Now that the lagoon is teeming with both alligators and iguanas, the lagoon is truly returned to the age of lizards and a semi-Triassic state.
When Kerans finally steps out of the elevator, Beatrice embraces him and asks if he's seen the alligators. He tells her that one nearly ate him and goes to stand at the window. The hydroplane is circling in the central lagoon, and Kerans comments that the alligators must be their guards. Beatrice comes and stands nervously by Kerans. She has continued to tend to her appearance for the last six weeks, but this new development appears to shake her composure. Kerans comforts Beatrice, telling her that they have nothing to give these looters.
The arrival of these intruders introduces the possibility of a conflict between men, not just between men and nature. However, Kerans's insistence that he and Beatrice have nothing to give is possibly false: as the story will show, Beatrice herself (because she is a beautiful woman) will prove highly desirable to the newcomer.
A big paddleboat enters the lagoon, loaded with gear and cargo. Kerans thinks that this is the group's “depot ship.” He figures that this crew is likely pillaging the drowned cities for heavy machinery. Such looting is technically illegal, but the authorities are usually happy to pay for the things looters pillage. Beatrice points to Dr. Bodkin down below on the testing station, who is hailing one of the crewmen. Kerans suggests that if they show themselves, the invaders will leave soon. He sees the hydroplane returning to Beatrice's lagoon and suggests that the pilot might give them a lift.
Again, human systems are breaking down even in the world government, as evidenced by the authorities purchasing looted items. Accepting these looters as possible friends shows that Kerans, Bodkin, and Beatrice returning to the present from their neuronic journeys. They're accepting both a sense of community and a forced return to the present and its pressing issues.