The novel describes escalating phases of what appears to be an invasion of Earth by aliens, as told through the eyes of Mike Watson, who works for the English Broadcasting Company (EBC) with his wife and co-reporter Phyllis. A major role is also played by Professor Alastair Bocker – more clear-minded and far-sighted about the developing crisis than everybody else, but with the habit of telling brutally unvarnished and unwanted truths.
Mike and Phyllis are witness to several major events of the invasion, which proceeds in a series of drawn-out phases; it in fact takes years before the bulk of humanity even realise that their world has been invaded.
In the first phase, objects from
outer space land in the oceans. Mike and Phyllis happen to see five of the "fireballs" falling into the sea, from the ship where they are sailing on their honeymoon. Eventually the distribution of the objects' landing points – always at ocean depths, never on land – implies intelligence.
The aliens are speculated to come from a
gas giant, and thus can only survive under conditions of extreme pressures in which humans would be instantly crushed. The deepest parts of the oceans are the only parts of Earth in any way useful to them, and they presumably have no need or use for the dry land or even the shallower parts of the seas. Bocker puts forward the theory that the two species could co-exist indefinitely, hardly noticing each other's presence.
Humanity nevertheless feels threatened by this new phenomenon – particularly since the newcomers show signs of intensive work to adapt the ocean deeps to their needs. A British
bathysphere is sent down to investigate, and is destroyed by the aliens with the loss of two lives. The British government responds by exploding a nuclear device in the same location.
Unfortunately for the humans, the aliens' technology proves formidable; an American attack ends in disaster. Moreover, humanity is not united in the face of the mounting threat – the
Cold War between West and East is well under way, with the two sides often suspiciously attributing the effects of the alien attacks to their human opponents, or refusing to co-operate because of their different political ideals.
Phase two of the war starts when ships all over the globe begin to be attacked by unknown weapons and are rapidly sunk, causing havoc to the world economy. Shortly after, the aliens also start "harvesting" the land by sending up biological "sea tanks", which capture humans from coastal settlements, for reasons that are never made clear; the Watsons witness one of these assaults on a Caribbean island. These attacks are eventually met with sufficiently strong retaliation from humanity that they become far less frequent.
And so, in the final phase, the aliens begin melting the polar
ice caps, causing sea levels to rise. London and other ports are flooded (the government relocates to
Harrogate), causing widespread social and political collapse. The Watsons cover the continuing story for the EBC until the radio (and organised social and political life in general) ceases to exist, whereupon they can only try to survive and escape a flooded London, relocating to a Cornwall holiday cottage which due to the floods now exists on an island in its own right. Other coastal countries are also disastrously affected - there is a reference to masses of
Dutch refugees fleeing into Germany, having "lost their centuries-long war with the sea".
Ultimately, scientists in Japan develop an underwater ultrasonic weapon that kills the aliens. However, the global population has been reduced to between a fifth and an eighth of its pre-invasion level, and the world's climate has been changed permanently.
Plot narrative
Up to the end, humans have no clear idea what their opponents looked like. The most they have is some protoplasm which floated to the surface of the sea after the ultrasonic weapon was used.
As stated in the book by the protagonist, the book aims to demonstrate that an alien invasion of Earth could take a very different form from that in
The War of The Worlds; publication of the book coincided with the release of 1953 film
The War of the Worlds, an adaptation of
H. G. Wells' classic work which was both a critical and
box office success.
Plot differences
Depending on the book's printed origin there are several changes to the plot:
- In the US edition almost an entire chapter on how the Watsons gained possession of The Midge yacht, and their aborted attempt to use a dinghy to get to Cornwall is cut, instead simply stating that Freddie Whittier "found it" one day.
- In the US epilogue, the Watsons are tracked down by Bocker via helicopter and he explains a great deal of what has happened to the world while Mike and Phyllis have been isolated - even describing the Japanese ultrasonic device in some detail. In the UK edition they are instead approached by a neighbour in a rowing boat, who gives them only a brief overview of what has happened in the world - excluding much of the detail and just mentioning that the Japanese have developed an ultrasonic device. He tells them that their names have been broadcast on radio, and that a "Council For Reconstruction" has been formed.
- The UK edition is less bleak than the US version, implying that humanity has already begun to rebuild, and that civilisation survives - albeit at a lesser level than before.
- There are several changes for a US audience in terms of language and phraseology.
