July 3, 1947. The crash of a spaceship, an event officially but never effectively denied by the United States Government, leaves three young aliens to grow up in the sleepy, backwater town of Roswell, New Mexico. Joined together by their common, otherworldly heritage, Max Evans (Jason Behr), his sister Isabel (Katherine Heigl) and Michael Guerin (Brendan Fehr) keep their true identities a secret from their families and friends. But the shooting of classmate Liz Parker (Shiri Appleby) forces Max to use his astonishing powers to save her life, and draws Liz and her best friend Maria DeLuca (Majandra Delfino) into the extra-terrestrial trio's secret world. On the periphery of this extraordinary secret, the aliens must also trust their real identities with the local sheriff, Valenti (William Sadler) and his son and Liz's former boyfriend, Kyle (Nick Wechsler).

Complicating their overwhelming desire to uncover the truth about themselves - who or what they are and where their true home might be - is the need to keep one step ahead of both terrestrial and extra-terrestrial adversaries.

Roswell explores the emotional drama of the ultimate outsiders - surviving descendants of alien beings - attempting to find their place among humans as they struggle with adolescence.