In this compelling series about the world's first encounter with an alien race, appearances can be deceiving. Simultaneously emerging and hovering over every major city in the world, the Visitors (or V's) promoted a message of peace, urging mankind to unite and claiming that Earth could learn much from the wonders of the V's technology. While the world quickly embraced the V's as saviors, FBI Counter Terrorist Agent Erica Evans (series star Elizabeth Mitchell) - at the time, investigating a terrorist cell - discovered that the Visitors were not who they said they were, and that they and their leader, Anna (series star Morena Baccarin), were after something far more devious and diabolical than anyone could imagine: the destruction of humanity.

Erica is now part of a group of resistance fighters called the Fifth Column, other dissidents who believe the Visitors have something to hide. Leading the group, along with Erica, are Father Jack (series star Joel Gretsch), a priest who was hesitant to believe in the righteousness of the V's from the start; Ryan Nichols (series star Morris Chestnut), who knows first-hand just what the V's are capable of; and Kyle Hobbes (series star Charles Mesure), a loose cannon and mercenary, he is the most ruthless member of the team.

Meanwhile, for Erica's teenage son, Tyler (series star Logan Huffman), the V's continue to fascinate. He sees them as his ticket to being a part of something big, something meaningful - and upon meeting the alluring Visitor Lisa (series star Laura Vandervoort), the two had an instant connection and undeniable chemistry. Chad Decker (series star Scott Wolf), a career-hungry news anchor, initially found that his exclusive interviews with Anna were crucial to his dominating the airwaves. However, after being diagnosed with a serious illness, Chad learns that Anna is manipulating him and turns to Father Jack for guidance ... and to join the resistance. But can Chad be trusted?