In a post-apocalyptic future, where global warming has caused the polar ice caps to melt, resulting in the inundation of major cities. Dr. Robert Kerans, a biologist, is part of a scientific team stationed in London, which has become a submerged, tropical lagoon. He is one of the few humans who have remained in the city, along with his colleagues Dr. Bodkin and Dr. Royce. The team is studying the natural evolution of the environment in this new world.
Kerans is suffering from strange dreams and visions of the past, particularly of the natural world before the flooding. He is intrigued by the increasingly tropical landscape of London, with its lush vegetation and exotic creatures. Kerans begins to feel a strong connection to the submerged world, as he experiences a sense of nostalgia for a pre-flood era.
The team's routine is disrupted when Lieutenant Hardman and his soldiers arrive in London on a mission to survey the area. They represent the military and the old world's values, which contrast with the scientists' more passive and observant approach. Kerans and his colleagues are uneasy about the soldiers' presence, as they disrupt the delicate ecological balance.
Kerans and Beatrice Dahl, a young woman living in the lagoon, form a
romantic and sexual relationship. Beatrice is captivated by the idea of exploring the remnants of the submerged city, and Kerans agrees to accompany her. Together, they venture into the city's flooded buildings, encountering eerie and surreal sights, such as a sunken world that has been reclaimed by the natural environment. Their exploration of this alien landscape deepens their connection and highlights the profound transformations that have occurred.
Dr. Kerans, Beatrice, and the team continue their exploration of the submerged city of London. They come across abandoned buildings and structures that serve as relics of the old world, now overrun by water and nature. Kerans becomes increasingly fascinated by the eerie and surreal landscapes they encounter. The group faces various challenges, including unpredictable weather patterns and the presence of mutated creatures, such as giant iguanas. The boundaries between reality and Kerans' dreams and hallucinations blur as he grapples with his own psychological transformation.
Kerans, Beatrice, and their companions continue their journey deeper into the flooded city. They discover a skyscraper known as "The Ritz," whichis partially submerged and houses a colony of primitive, semi-aquatic humans known as "swimmers." The swimmers live a tribal existence and communicate through a primitive language. Kerans is both fascinated and disturbed by their existence and the way they have adapted to the new environment. The swimmers are hostile, and the group barely escapes from an encounter with them.
As Kerans and his group press further into the city, they encounter signs of an ancient civilization known as the "solarite culture." They discover a mural on a building that suggests the culture's fascination with the sun and the tropical climate. This find deepens Kerans' sense of
connection to the past and the psychological forces driving his fascination with the submerged world. The group's encounters with the natural and human elements of this transformed world continue to test their resilience and adaptability.
The military presence led by Lieutenant Hardman becomes increasingly aggressive and authoritarian. Hardman is determined to exert control over the scientists and enforce traditional values. Kerans and his companions feel threatened by the military's intervention and the potential for conflict. The group must navigate the complex and evolving dynamics of their relationships with each other, the swimmers, and the military, all within the context of a world undergoing profound ecological changes.
Dr. Kerans and Beatrice continue their journey deeper into the submerged city. They come across the submerged ruins of a former government building known as the Whitehall Palace. Inside the ruins, they discover a room filled with a vast collection of precious books and artwork that have been preserved by the water. This discovery reveals the extent of the lost world's cultural treasures and provides insight into the civilization that once thrived in the city. The encounter with these preserved artifacts deepens Kerans' sense of nostalgia and connection to the past.
The military presence under Lieutenant Hardman becomes more oppressive, and their control over the scientists and the swimmers intensifies. Hardman is determined to assert his authority and restore the values of the old world, seeing the scientists and their exploration of the submerged city as a threat to that order. Tensions rise as Kerans and his companions navigate the power struggle between the military and their scientific pursuits.
Kerans, Beatrice, and their group continue to delve deeper into the submerged city, encountering the remnants of the old world's technology and infrastructure. They explore abandoned vehicles, observe thedecay of human structures, and witness the encroaching growth of vegetation. Kerans reflects on the role of nature in reclaiming the city and the insignificance of human accomplishments in the face of ecological change. The novel continues to blur the line between reality and Kerans' increasingly dreamlike experiences.
As the narrative progresses, Kerans' connection with Beatrice deepens. Their relationship becomes a central focus, as they explore the psychological and emotional dimensions of their journey through the flooded city. They share moments of intimacy and vulnerability as they navigate the challenges of the submerged world and the ever-present military presence. Kerans' evolving feelings for Beatrice are intertwined with his fascination with the submerged landscapes and the mysteries they hold.
As Dr. Kerans and Beatrice continue their exploration of the submerged city, they encounter signs of the former civilization's decline. They discover a series of abandoned high-rise buildings with rooms filled with sand and encroaching vegetation. The remnants of the old world are gradually being consumed by the relentless forces of nature. The city is depicted as a surreal and dreamlike landscape.
Kerans and Beatrice also encounter the remnants of a luxury yacht and take refuge on it for a period of time. The yacht serves as a brief respite from their journey through the submerged city.
The presence of Lieutenant Hardman and the military continues to loom large over Kerans and his group. Hardman is determined to assert control and enforce discipline, seeing the scientists and their pursuit of knowledge as a threat to his authority. Tensions escalate, and the conflict between the military and the scientists comes to a head.
Kerans, Beatrice, and their companions must navigate this growing conflict while also facing the ever-evolving challenges posed by the submerged world and its strange inhabitants.
Dr. Kerans and Beatrice come to a decision about their future. The relationship between the two has deepened throughout their journey, and they must confront their feelings and choices. The submerged city and its dreamlike landscapes continue to exert a powerful influence on their perceptions and emotions.