The chaotic aftermath of an alien attack has left most of the world completely incapacitated. In the six months since the initial invasion, the few survivors have banded together outside major cities to begin the difficult task of fighting back. Each day is a test of survival as citizen soldiers work to protect the people in their care while also engaging in an insurgency campaign against the occupying alien force.
Live And Learn
In the opening scene, young children tell their versions of the invasion. They draw pictures of their families, kids with harnesses and the alien airships. Tom Mason's son, Matt, tells Anne Glass that his mother died during the attacks and his older brother, Ben was kidnapped. He then shows her a picture of his father and older brother, Hal. Matt informs Anne that they are fighting. In a dark street, Tom and Hal look for food. They grab a food kart, but are ambushed by robotic aliens, known as "Mechs", which destroy the food. As Tom and Hal run away, soldiers fire guns at the aliens behind barricades. The aliens destroy the barricade and kill the soldiers. Tom and Hal hide in an empty store. They exit, finding Weaver and other soldiers armed with guns. An airship flies overhead and fires, causing a bright light to consume the atmosphere around them. The group runs away back to their base.
Upon arrival, Tom sees his son Matt asleep and picks him up. He talks to his friend, Anne who tells him about his son's drawings. Tom is then called by Col. Porter for a meeting. There, Porter discusses his plan to leave the city and break off into groups. The alien air ships can detect groups of humans over 600 persons so he splits his brigade into smaller groups consisting of 100 fighters and 200 civilians. He puts Weaver in charge of the 2nd Mass and Tom as his second-in-command.
The following day, the fighters and civilians begin to move. They search for food in stores but find none. Weaver tells Tom that they can't go back looking for more food as the numbers are too large. Tom volunteers to go back. Weaver gives him six fighters and a pickup truck. Hal, Karen, Dai, Anthony, Click and Jimmy join Tom in the hunt for food. Hal and Karen leave the group to search for aliens. Hal sees Mechs and harnessed kids with them. It is there that he sees his brother, Ben. He immediately returns to tell his father. They are both overjoyed, yet Tom insits that they stick with the mission at hand. Hal disagrees and tries to go and find his brother. Tom wrestles him to the ground and convinces him to do the job the "right way".
The group finds a supply store with food and scout the area for aliens. Finding none, they load the food into the truck. Hal is attacked by a Skitter. Tom fires at it and his son runs away. A Mech is alerted and comes after Tom. Hal stops the it by firing at it. It then runs after Hal. Tom puts C-4 in a shopping cart and wheels it next to the Mech, killing it. The Skitter comes after Tom, but Dai shoots it. The alien dies slowly after its gun wound and the group observes it before it dies.
The six fighters return and Tom informs Weaver of their success. He then tells Weaver that he and Hal must go looking for Ben. Weaver declines and says they must raid the armory for weapons. Tom tells him after that, they will go and find him. Before the 2nd Mass leave the city, Hal gives his brother his birthday gift. The children of the 2nd Mass play with it as the adults watch. Weaver tells Tom it is time to leave and they all mount out on foot.
The Armory
At the Armory, Tom and the other members gather to see if aliens are present. Hal throws a tennis ball to the entrance, hoping that the dog will go for the ball. The dog moves forward, barking and a "mech" appears. Before it can kill the dog, Jimmy stops it, compromising their position. They all move before the Mech attacks.
The next morning, Tom informs Weaver about the previous night's events. He tells Tom to return again tonight. Anne then confronts Weaver about the current sleeping situation, where civilians are living in tents and the fighters in houses. Anne deems it unfair, yet Weaver believes the soldiers need proper rest. Anne and Tom then discuss "civilians vs the military". The pair then watch Uncle Scott teach the young kids about biology. Later, Uncle Scott talks to Tom about the aliens. He points out that robots humans created were made to look human, with two legs, yet the Skitters' mechs also have two legs, despite a Skitter having six. Tom theorizes the Skitters may have studied Earth before the invasion, and deployed bipedal machines as a form of psychological intimidation. After running in to Lourdes, Karen talks to Hal about her intention. Hal doesn't seem to care about Lourdes and kisses Karen. Tom interrupts, telling Hal they are due to return to the Armory later.
Later that night, the group get ready. Jimmy is told that Click will be going in his place which disappoints him. At the Armory, Click is shot and killed by two arrows and as he goes down, he shoots someone in the leg. It is revealed to be not aliens, but a group of outlaws who capture the group. The outlaws, led by a man named John Pope, take the group to an auditorium, tying them up. Pope interrogates them and Tom responds to all his answers. Pope pulls a gun on Tom, but Hal tells him that they can help him get weapons. Hal is led out of the auditorium by Margaret, a woman in Pope's gang, who gives him one hour to go back and get guns from the 2nd Mass. Tom and Pope discuss the aliens and Tom discovers that Pope is a gifted fighter. Tom asks for a beer and untied by Pope, who notices Tom eying his brother's sidearm. He confronts him about it and Tom asks "What would you do?"
Hal returns and informs Weaver about the situation. Weaver says they will not trade with Pope and orders Mike to take Hal upstairs as prisoner until they are ready to leave. Mike, however, allows Hal to leave and on the way, Hal runs into Anne, who offers her assistance. They both return to find Margaret who escorts them back to Pope. Anne offers her assistance in relation to Pope's wounded brother, Billy. She bandages up his leg and Pope leaves him, Cueball and Margaret in charge of the prisoners as he and his other outlaws attempt to rob the 2nd Mass.
Pope sends a flare into the air to alert the airships, giving Weaver an ultimatum. Weaver reluctantly agrees and hands over food and ammunition. Back at Pope's base, Billy, Cueball and Margaret hold Tom and the others captive. Billy tells Karen to stand up and show her body, aggravating Margaret, who kills Billy and Cueball. She then lets the hostages go.
As Pope and his group load up the car, Tom and the other militia fire at them with guns, killing some of Pope's men. Tom offers him and ultimatum: "Join or die." Pope declines and waits for the alien's attack. An airship flies above Pope, who drives away, allowing his men to be killed by the ships. Pope pulls aside not far away, trying to escape, but Weaver pulls a gun on him, taking him hostage.
The next day, Weaver talks to Tom about the events that occurred the previous night. He then hands Pope over to Tom, who puts him in custody. Tom meets up with Matt for a quick game of catch. After, Tom, Hal, Karen, Dai, Anthony and Margaret go in search for Ben at a local hospital.