It's 2050, Earth is dying, victim of the deforestation, pollution and overpopulation. Colonizing Mars is the only possible alternative to the annihilation of the human race. During twenty years, the Earth sent on Mars seaweeds that have allowed to feed Mars in oxygen so as to generate a sufficiently rich oxygenated environment to provide to the human life. Kate Bowman is the commander and pilot of the most important mission of the 21st century. Bowman and her crew composed with the most eminent specialists leave to inquire on the reasons of the quick decline of the rate of oxygen risking to put in peril the Terraformation project of the planet Mars.
But their arrival after a 180 days trip is chaotic. A Gamma radiation coming from a solar eruption destroys a great part of the ship's equipments. The crew, excepted Bowman who remained in the spaceship must withdraw in the launching capsule that was to be used to land on Mars, and has no other choice that to be released from the mothership. Bowman has to face a critical situation when fire invades the ship and when extinguishers no longer get circumscribe. In a last attempt, she dresses a space suit and opens an external trap so as to smothering the fire that gnaws.
For Gallagher, Burchenal, Santen, Pettengill and Chantillas, the exploration team that comes to land in emergency on Mars, the problems are just beginning. Chantillas cannot go farest, the rough landing of the capsule exploded his spleen. While he remains on place, the rest of the team leaves in search of HAB, an advanced position deposited on Mars during one of a preceding automated mission. Deprived of communication means and only 19 hours of oxygen left, they have to find the station urgently.
Burchenal have pain to understand what happened. Normally the valleys they cross would be spread by a huge rug of seaweeds but it is not the case, the landscape is red and very rocky.
When they arrive, they have the bad surprise to find HAB completely shredded and out of oxygen reserves, water, food and radio. The four astronauts are quickly going to perish by lack of oxygen.
While they are at a distance from the other members of the expedition, a violent dispute between Santen and Pettengill ends by a fight to death. Pettengill will explain that Santen committed suicide and that he couldn't do anything to save him. As if all that was not enough, EMY, the little military exploration robot finds them back. Previously ejected from the capsule during the descent on the planet, the polymorphous robot undergoes a serious malfunction. Consequently, instead of helping the astronauts, it uses its military program and considers these ones as enemies that it has to destroy.
But reserves of oxygen are exhausted and arrived to term. Gallagher is the first touched. While he suffocates and is on the way to die, in a last gesture, he subtracts his helmet. Surprise, the air of Mars is breathable, this miracle fact is extraordinary and incomprehensible for the astronauts.
It is necessary at any costs to contact Bowman by all means who is always in orbit around Mars attempting to notice her team on the ground. Gallagher decides to find an ancient probes sent in the eighties very near HAB hoping to retreive there a transmitter that would help them to enter in contact with Kate. After some manipulations, the ground team succeed to contact the spaceship in orbit on a so old frequency that the Earth first capt them before broadcasting it to Bowman.
Kate Bowman delays the time of departure and tries to find a solution to recuperate her team. The unique chance consists in finding Cosmos, a Russian probe landed on Mars in the last century but that had never been able to take back off. Unfortunately, even if the team dabbles the probe in order that it takes off, Cosmos could only embark a maximum of two persons in the samples lockers.
The probe is localized a hundred of km far from there, the three survivors put on the way. On the path, they have to wipe a huge depression that nails them in a shelter of fortune during three precious hours. Indeed, their time is counted. Because of the lack of fuel, Bowman cannot remain in orbit indefinitely if she wants to be able to join the Earth. All calculation made, astronauts will have only one hour to repair the soviet probe. But Pettengill profits the sleepiness of his comrades to escape with the transmitter to find the probe before them. Unfortunately for him, he forgot the presence of EMY, always in search of its enemies that finds and kills the astronaut.
Later, Gallagher and Burchenal launch to his pursuit and find him. But, Gallagher notices that the body of Pettengill is stuffed with little carnivorous insects and takes some in sample. He understands now why without seaweeds, the red planet possesses nevertheless oxygen...
Spoiler ! the end of the story is revealed below…
Where there is air, there is life. These insects have devoured seaweeds sent on Mars since these last twenty years and by an unknowned miracle, they produced oxygen in their tour. These beasts, nevertheless capable of destruction, represent now the last hope of the humanity.
Without no more news of the ground team, Bowman who succeeded to put all systems operational must prepare to the trip back. On the ground, millions of insects surround Burchenal and run towards him. The former, well decided not to perish as Pettengill releases a mini nuclear load after having given to Gallagher the essential sample for the humanity and his oxygen reserve he will need. The shock wave attracts the Bowman's attention. Hoping Gallagher will succeed to take off with the soviet probe, she decides to wait a bit more.
Arriving near the probe, his hopes are short. The probe battery is out of order and without it, it is impossible to take off. The last hope of Gallagher consists in recuperate the energy cell of EMY that will quicky find him. Gallagher prepares a trap in which falls and perishes the robot. The cell of energy in hand, Gallagher takes off on board the probe. Bowman manoevers to recuperate her team-mate. Taking all risks, she repatriates Bowman in extremis. Together, they can now return back on earth with the answers that are going to save the humanity.