With an alien invasion in progress in China, humanity is divided on how to defend itself. The Chinese government is determined to go it alone, despite suffering catastrophic losses. Captain Wit O’Toole of the Mobile Operations Police (MOP) and Mazer Rackham have managed to destroy one of the three alien landers, but because they achieved the first significant human victory of the war without official approval and using a nuclear warhead obtained without authorization, they are in the custody of Chinese General Sima. During the invasion, Mazer Rackham saves Bingwen, a very intelligent eight-year-old Chinese boy who now comes up with a clever ploy to get them released: he spreads word over the internet that they were acting under Sima’s orders and gives Sima full credit.

Meanwhile, Victor Delgado and Imala Bootstamp drift to the alien mothership in a ship disguised to avoid being destroyed. Victor manages to enter and explore the vessel. They survive a failed drone attack on the alien ship and, after getting away again, confront Lem Jukes, whom they suspect of involvement in the attack. Actually, it was launched by Lem’s father, Ukko. Lem tried to stop or delay it.

Based on what he has learned, Victor devises a plan to capture it, and reluctantly accepts Lem’s help in carrying it out. The MOPs, including Wit and Mazer, are recruited to become the rest of Victor’s boarding party. Despite Victor’s objections, Imala volunteers as well.

When the Formics detect the intruders, all of their forces on Earth leave to go to their ship’s defense. Lem leads a force to hold them off, resulting in a fierce space battle. Aboard the Mothership, Wit has to sacrifice his life, exposing himself to quickly lethal levels of radiation, but Victor’s plan succeeds, and the ship is captured intact. However, Victor’s cousin, Edimar, backtracks the path of the alien ship and discovers that it was only a scout ship; the real Mothership is reconfiguring itself into a battle fleet that will arrive in about five years.

A century before the events of Ender’s Game, an alien spaceship enters the solar system and soon makes known its hostile intentions by destroying harmless human ships. Then, it wipes out a ragtag fleet of asteroid miners who have banded together in a desperate attempt to stop it. All of the adult male members of Victor Delgado’s extended clan die in the battle. The survivors are unable to transmit a warning, so Victor volunteers for a near-suicidal mission to try to reach Earth in a tiny, hastily converted unmanned cargo ship. He makes it to the Moon, but is unable to get the authorities to take him seriously. Thus, humanity is totally unprepared when the First Formic War starts.

The invader sends three enormous landing craft to southeast China. The Formics emerge and use gas to defoliate the area and kill everyone. Despite suffering stupendous losses, the suspicious Chinese government refuses outside help.

Before the landing, Mazer Rackham had been training the Chinese military on a new transport aircraft, the HERC, in exchange for training on their new invention, drill sledges that can tunnel quickly underground. During the Formic invasion, he saves Bingwen, a very intelligent eight-year-old Chinese boy, but is then shot down. Bingwen saves his life, with the remote help of Mazer’s romantic interest, Kim. Bingwen and Mazer then set off to destroy the nearest Formic lander.

The Mobile Operations Police (MOP), a small but elite international force, enters China (without official authorization). The MOPs save Bingwen and Mazer from a Formic attack. The lander is heavily shielded, but it does not extend underground. Mazer manages to find some drill sledges and HERCs to transport them close to the lander. MOP Captain Wit O’Toole obtains a tactical nuclear weapon from anonymous Chinese who do not agree with their government’s stance on foreign assistance. They destroy the lander, but then Captain Shenzu arrives and places Mazer under arrest.

Meanwhile, Victor and Imala (a Customs Agent assigned to Victor upon his unauthorized arrival) manage to drift close to the Formic ship, using a disguised ship provided by Lem Jukes (the only son of the richest man alive) to avoid being destroyed. Victor breaks into the alien ship through a gun port.

A family of “free miners” living on the spaceship El Cavador is working an asteroid far out in the Kuiper Belt when they detect what appears to be an alien ship decelerating from near light speed as it approaches the solar system. Meanwhile, Lem Jukes, son and heir of the hard-driving founder of the largest mining corporation, is also in the remote region, far from the prying eyes of competitors, secretly testing a “glaser” (gravity laser) that promises to revolutionize mining. Back on Earth, Captain Wit O’Toole goes recruiting among the elite New Zealand Special Air Service for the even more select, multinational Mobile Operations Police (MOPs).

Jukes orders his ship to “bump” El Cavador from the asteroid the family is mining, as it is the only suitable one nearby for his test. During the violent collision, an El Cavador crewman is killed. The miners hack into the corporate ship’s network, planting a message for Lem Jukes and downloading confidential files pertaining to the glaser. Jukes, fearful of a scandal involving the death of a free miner and the danger of the miners selling the confidential files to his competitors, sets out for Weigh Station Four, where he intends to plant a hacker to strip El Cavador’s files.

El Cavador’s transmission equipment having been destroyed in the bump, the crew are unable to warn another mining clan about the intruder, and can only watch helplessly as the alien pod destroys them. El Cavador rescues a few survivors. In the meantime, Victor and a few others modify a “quickship,” an automated vessel normally used to send processed metals to Luna, to carry one person to warn Earth. When the pod attacks El Cavador, the men on the quickship ram and disable the pod using mining equipment. During the attack, the aliens emerge to battle the humans. Their physiology is revealed to be Formic (ant-like).

El Cavador heads to Weigh Station Four to use their laserline transmitter. As a backup, Victor volunteers to take a datacube with the evidence of the aliens’ hostile intentions to Luna aboard the quickship. The journey is perilous, but their duty is clear.

Meanwhile, the Juke ship makes its way to Weigh Station Four, only to come under attack from roughnecks who recognize the crew as despised corporates. Several of the attackers are killed by Chubs, a man seemingly junior to Lem Jukes, but revealed as having been assigned by Ukko Jukes to protect him. The corporates are still able to leave behind a hacker to strip El Cavador’s files, but the scheme becomes moot when the Formic ship destroys the station.

El Cavador sends a short-range, broad radio call and is able to contact the Juke ship and a Chinese mining vessel. El Cavador sends its women and children aboard the Chinese vessel, which is too small to help in the attack. The plan is to plant mining explosives along the hull of the alien ship. Unfortunately, one of them detonates early, drawing the attention of the Formics, who at first engage the humans wearing space suits, but subsequently attack without any protection. Seeing the battle go against them, Chubs withdraws Lem Jukes and his men and moves the corporate ship away, as the Formic ship destroys El Cavador.

Victor arrives at Luna, only to be largely ignored and confined for his illegal arrival. Meanwhile, Wit O’Toole prepares his MOPs for any situation, including what he thinks is a hypothetical alien attack. Victor is eventually assigned a case worker who believes his story and helps him transmit the evidence onto the Nets