The Drowned World
by J. G. Ballard
In the late 21st Century, sudden violent and prolonged solar storms enlarge the Van Allen belts, leading to a deterioration of the Earth's ionosphere. Solar radiation bombards the planet, increasing temperatures, raising sea levels and imposing a tropical climate worldwide. With most of the planet no longer habitable for humans, the survivors migrate to the newly-hospitable poles.
In 2145, Dr Robert Kerans is part of a scientific survey unit under the leadership of Colonel Riggs sent to catalogue the flora and fauna of a lagoon located within what was once the city of London. The members of the expedition begin to experience strange dreams. Amidst talk of the army and scientific team moving north, Lieutenant Hardman, the only other commissioned member of the unit, flees the lagoon and instead heads south; a search team is unable to prevent his escape.
As the other inhabitants of the lagoon finally flee the searing sun and head north, Kerans and two associates, the reclusive Beatrice Dahl and fellow scientist Dr Alan Bodkin, opt to remain. A team of pirates, led by an individual named Strangman, arrives to loot treasures within the deep. When Strangman and his team drain the lagoon and expose the city beneath, both Kerans and Bodkin are disgusted; the latter attempts to blow up the flood defences and re-flood the area, but without success. With Kerans and Beatrice resigned to their fate, Strangman pursues Bodkin and kills him in revenge.
Strangman and his team grow suspicious of Kerans. He and Beatrice are imprisoned, while Kerans is then tortured. He survives, although severely weakened by the ordeal, and attempts to save Beatrice from her imprisonment, to little avail. With Kerans and Beatrice facing the guns of Strangman and his men, the army under Colonel Riggs returns to save them at the last moment. The authorities co-operate with Strangman rather than punish him and Kerans once more grows frustrated by the inaction, finally taking a stand and succeeding in re-flooding the lagoon where Bodkin had failed.
Wounded and weak, Kerans flees the lagoon and heads south without aim, meeting the frail and blind figure of Hardman along the way. After he aids Hardman back to some amount of strength, he soon continues onwards on his travels south, "a second Adam searching for the forgotten paradises of the reborn sun".