Due to interference by the invaders while the pregnant Anne was held hostage, Lexi is a hybrid of human-alien DNA.
Season four finds Tom in a concentration camp similar to the ghettos of the World War II era.
By season four Hal is his father's second-in-command, leading the ghetto resistance while Tom is held in solitary confinement.
In season two, Weaver finds his daughter; she, her boyfriend and their surviving group leave separately and reunite in Charleston.
Promoted to colonel between seasons two and three, he is a key advisor to Tom Mason in his role as President of the New United States.
In season 4, she is mortally injured in a massive Espheni attack on Chinatown and Ben gives her three of his spikes to heal her injuries.
Pope is apparently killed in an explosion caused by Tom Mason and Colonel Weaver during an attack on the 2nd Mass' headquarters.
After Tom wipes out the Espheni and loses Anne, Pope confronts him on the beach he is waiting on in hopes the Dornia will save her.
During the final battle, Weaver has him lead a team to hold their base in Norfolk, Virginia which he reluctantly accepts.
After the destruction of the Boston mothership, his father arrives and Cochise defends humanity's right to help fight the Espheni, something the Volm never allow.
Cochise refuses to, believing in humanity and his new friends and stays behind with a small group of Volm soldiers to continue the fight with the Espheni on Earth.
In season 4, he aids the humans in their plan to destroy the Espheni power core and manages to get his father to return to lend a hand.
Cochise helps explain the situation to another militia leader that arrives and is part of Tom's strike team to kill the Espheni Queen.
Months later, Cochise is part of a Volm delegation who attends Tom's speech and the choosing of a new leader for a united humanity.
Originally thought to be the alien species responsible for invading Earth, the Skitters are a race under control of the Overlords.
Those who control mechs can put them into guard/patrol mode, give special orders violating their usual protocol and assign priority targets.
In season 4, the Scorched Overlord reveals that part of the Espheni motivation is that they are running from their great enemy, the Dornia, and are conquering worlds to fuel their war machine.
They serve a queen who states that the second reason for their attack is revenge for the death of her daughter during a failed invasion 1,500 years before the one in the series.
Lourdes hosted several eye worms, making her kill multiple people, including the President of the United States, and causing her extreme pain until Alexis removed them.
In Season 4 the greater Volm forces leave Earth to engage the Espheni, who in the meantime attacked their young and brood mates.
The Espheni are destroyed by Tom Mason in the series finale, Reborn, with a Dornia bioweapon and the Volm war with them ends.
A Volm delegation including Cochise attends a united humanity's gathering to choose a new leader months after the invasion ends.
Their tails are prehensile and incredibly strong, allowing them to effortlessly carry objects as big as a grown man into the sky.
One Dornia appeared to Tom after his Beamer was flung to the edge of the Solar System, creating a room that mimicked his Boston bedroom.
Six weeks before the 2nd Mass encountered the 14th Virginia, the Espheni killed militia leader Captain Katie Marshall and replaced her with a clone who took commands from an Overlord who kept an eye on her base.
Under the command of this copy of Marshall, the 14th Virginia began hunting what they believed were human collaborators but were actually resistance soldiers dangerous to the Espheni.
Enraged, the Espheni Queen vowed to return a thousand times stronger to wipe out humanity in revenge for her daughter's death.
According to an Espheni-generated clone of Alexis Glass-Mason, the Queen only comes to a planet when victory is certain and that her presence means that the Espheni are switching objectives from invasion to occupation.
Ben begins using the device to try to locate the Queen who creates a clone of Alexis Glass-Mason to try to assassinate Tom Mason, the human resistance leader.
The Queen pins Tom to a wall with webbing and telepathically shows him the true reason for the Espheni invasion and believes that when she kills him, human resistance will fall.