V

In the highly anticipated and compelling series premiere, the Visitors (V's) are initially viewed with fear, but quickly become a fascination. Elizabeth Mitchell stars.

Erica and Father Jack find themselves being tracked by a "Seeker" from the V's. Chad, who is not happy with his first interview with Anna, determines to become more investigative.

Chad reports from the Peace Ambassador Center as visas are issued to the first wave of Visitors, including Anna. Erica, paired with a V officer, begins tracking a death threat.

Erica works with newly formed allies to uncover a biological threat they suspect the Visitors have been plotting. Plus, Anna befriends a special guest inside the mothership.

Erica finds her life in danger when she's attacked at home, and the Visitors build up their defenses. Anna is upset with Chad and Ryan is concerned about Val's pregnancy.

Anna invites humans to stay on the spaceships, Ryan is concerned that Valerie's pregnancy is going too fast and Tyler learns a secret about his mom, Erica.

Erica, Ryan and Jack go on a harrowing mission to find the legendary John May (MICHAEL TRUCCO -- Battlestar Galatica) in order to rescue Georgie (David Richmond-Peck).

Erica, Jack and Hobbes (CHARLES MESURE) take measures to protect the Fifth Column members. Ryan reveals to Val that he is a V. Chad boards the Mothership to heal his aneurysm.

Ryan, Father Jack and Hobbes (CHARLES MESURE) try to avoid a team of deadly V trackers. Anna invites Tyler to live on the Mothership. Chad confronts Jack about the Fifth Column.

After a violent attack on someone close to Anna, she decides it's best to leave. Erica and the team try to find a scientist who may have created a weapon the V's are afraid of.

In the season finale, Val's water breaks -- her baby with Ryan will be born. Erica goes on the offensive aboard the Mothership. Chad finds out Anna has been using him.