Years ago, the Taelons came to Earth, offering friendship and technology to humanity. But there are those who believe the Taelons have more sinister motives.
The joining of the Taelons and the Jaridians create the Avatus race, a greater threat that Renee leads the fight against.
Sandoval strikes a deal with the Atavus while Renee tries to convince Hubble Urick about the existence the aliens.
Renee fights to destroy the Atavus as they begin a joining process that will create human-Atavan hybrids.
Renee, with a former reporter, tries to inform the media about the Atavus.
William Boone, the Taelon Protector who secretly led the human Resistance movement three years ago, is awoken from a state of suspended animation aboard the Mothership by Sandoval. He awakens to find that the Taelons and Jaridians have merged to become a new alien species posing an even greater threat to humanity and joins Renee's crusade against the Atavus.
Renee breaks out a serial killer from prison, hoping she will be able to provide the information necessary to kill the deadly Atavus aliens, but the plan backfires.
Renee attempts to sabotage Sandoval and Howlyn's plans for producing Atavus regeneration chambers.
Renee visits Boone and shows him a crystal that can project the location of every Atavan on Earth. In an effort to retrieve the crystal, Sandoval brings Zo'or back to life as an Atavus so that she can battle her old nemesis Boone.
A young woman, J Street, finds herself attracted to a seductive Atavus.
Renee travels back through time in pursuit of a deadly female Atavus.
Renee suffers an emotional breakdown after a high-rise attempt to rescue a woman and her baby from an atavus attack goes horribly wrong. Unable to shake the image of the crying baby falling to its death, Renee and Street check into a spa to try to relax. Her therapy is soon cut short as they find themselves being stalked by Howlyn.
After he sets up an Atavus fan Web site, a disaffected teenager is used by the Atavus to recruit the world's youth into its army of hybrids.
This pivotal episode brings Renee Palmer to a hybrid-infested hospital where comatose patients are being used as a food source for the Atavus. It is only when Renee is ultimately able to expose these atrocities that the FBI finally takes seriously the threat of the Atavus, who must feed on the life force of humans in order to survive. The FBI pledges to join Renee's crusade to destroy this formidable alien menace before they take over the world.
Juda's death spells hope for Renee in her battle against the Atavus.
Renee receives part of an old manuscript from an associate of her Harvard professor, who believed that ancient Egyptians were visited by aliens. He claims he has discovered proof of this and then disappears. Renee visits the Giza plateau and fins she must hook up with an old flame, in fact her love, Raleigh Sinclair, who's a dashing British scoundrel and a rogue archeologist. The two must work together to search the Pyramids to locate the tomb of Askenaton, a Grand Vizier to the Pharaohs and possible ancient Atavus who had mystical powers. Renee and Raleigh have some good hot-tempered banter as they try to outwit each other, while Sandoval arrives to complicate things further.
Renee has a change of heart and sympathy for her unwilling enemy as she becomes aware of the inhumane treatment the atavus hybrids must endure in government run internment camps.
Renee and boyfriend Captain Michaels "do-the-right-thing" as they risk their own personal integrity in an attempt to secure plans to the one military weapon that can kill the atavus.
Renee's personal image of mankind's greatest enemy is forever changed when she becomes emotionally involved with a young atavus child, Yulyn, whom reveals he has a very human-like soul. Renee must now protect Yulyn, also a royal, from Howlyn's evil clutches.
Renee is put on trial for opening an Atavus stasis chamber.
J Street has become an Atavus hybrid, Renee rushes to locate an antidote.
Renee hooks up with Captain Michaels to investigate a pharmaceutical plant manufacturing an Atavus Hybrid vaccine. But something is a little strange about the lead scientist Dr Spangler. Ra'jel returns to lead Renee on an enlightening trip down memory lane. Why did the Taelons pick Earth? Things take a very deadly turn at the lab; Michaels is seriously injured, Dr Spangler's truth is revealed, and, as the Captain fights for his life, Renee must make an awful final choice.
As Renee begins to lose hope that humanity will survive, an old friend reappears to give her guidance and solace. Yulyn and Ra'jel will join forces to deliver the final blow to the atavus threat to mankind. Sandoval comes to term with his past, and ends the series in a very fitting "Sandoval" manner.