An alien race arrives in massive space ships hovering over major cities all over the world, offering friendship and advancements. But an F.B.I. agent learns that the Visitors have ulterior motives.

Erica joins the Bureau in an investigation of her partner Dale's disappearance, not knowing who she can trust with her secret. While the U.S. debates official diplomatic relations with the Visitors, Decker tries to take back control of his relationship with Anna, and Nichols seeks out an old acquaintance for help.

As Anna and the Vs are granted diplomatic visas by the United States, Agent Evans is tasked to defend them from a death threat. Jack finds a lead on the head of the warehouse meeting, and Dale tries to recover the memory of who learned his real identity.

Erica and her new underground allies target a Visitor who has been posing as a human, while Erica suspects Ryan's intentions. Anna investigates a murder on board her ship, and Decker reports on the Vs incredible healing centers.

When the Vs point to a wanted criminal (rather than the Fifth Column) as responsible for the warehouse explosion, Erica tries to recruit him against their common enemy. Val grows concerned about her strange pregnancy, and Anna takes steps to create a new army.

Anna plans to invite humans to live on V ships, while also testing her people for Fifth Column sympathizers. Erica takes her son to see his father, and Ryan infiltrates one of the ships to broadcast a call to arms to the worldwide resistance.

Ryan, Erica, and Jack go in search of John May, the original founder of the resistance -- with whom Ryan has personal history. Lisa interrupts Erica's plans to hide Tyler away at his father's, and Georgie is tortured for information on the Fifth Column.

Anna addresses a U.N. summit to present world with the gift of a new form of energy, while the Fifth Column tracks down the survivor of a Visitor attack who may have info on other resistance cells. On the mothership, Joshua is surprised when Lisa fails his human sympathy test.

Ryan takes Valerie into hiding from the Vs, and Anna releases a violently powerful soldier to find them. Chad prepares for his surgery, and Erica tries to uncover her new prisoner's real motives.

The resistance movement shoots down a V shuttle believed to be carrying a team of trackers sent to hunt them down, and must deal with the blowback after learning the shuttle actually carried innocent human passengers. Meanwhile, Chad goes to Father Jack in the hopes of getting close to the Fifth Column.

Anna leverages the attack on Lisa to gain sympathy against the Fifth Column, announcing that the Vs are leaving Earth. Meanwhile, Erica searches for a scientist wanted by the Vs and the F.B.I.

Erica goes aboard the mothership with plans to destroy Anna's incubating soldiers, and Joshua turns to Lisa for help. Ryan goes after Anna after Val is taken during labor, and Chad's loyalties are tested.