Brody Davis, the mysterious new curator at the UFO Museum has the group on edge, and Michael and Isabel plotting his demise.

Max and Tess depart for the interstellar summit in New York City with Rath and Lonnie, Michael and Isabel's duplicates, who both harbor a secret agenda for their future king and an alliance with Nicholas, the Skin. Ava reveals to Liz that Rath & Lonnie murdered Zan. Tess is kidnapped by the dupes after Max learns of their true intentions. When Max finally finds Tess she reveals that they tried to read her mind to find the Granolith but she resisted. She then says that they're gone but did they die or are they still out there? Ava says goodbye to Liz and leaves Roswell.

Michael and Maria flee from Roswell after helping Laurie DuPree escape from the police, and Max learns that a deadly parasite was released into Earth's atmosphere when their ship crashed 50 years ago.

Max tries to stop Alex and Kyle from being buried alive in a cave filled with glowing blue crystals; Isabel is kidnapped by Grant Sorenson possessed by the alien parasite queen; Michael is shot while trying to protect Laurie.

The sudden death of a close friend shocks the group.

Michael works as a security guard, but when he tries to loosen up his co-workers, he causes more harm than good. Meanwhile, Max and Liz continue to see each other despite her parents' wishes.

Right before her wedding, Isabel is torn with doubt when she has erotic dreams of her former alien lover, Kivar. Meanwhile, a reluctant Max agrees to serve as Jesse's best man, while attempting to investigate him at the bachelor party.

When a journalist friend of Jesse's comes to Roswell, Isabel discovers he's investigating her, Max and Michael, after he witnesses Michael using his powers. Meanwhile, Isabel fantasizes about what her life would be like if Jesse knew her alien secret through the device of a 1960s sitcom a la "Bewitched."

Michael, Jesse and Valenti call on a discredited doctor to help the wounded Isabel. Also, Clayton Wheeler undergoes an amazing transformation and soon finds himself drawn to Liz; and Jesse quizzes Michael about Isabel's alien roots.

As their high school graduation approaches, the gang must come to terms with their expectations for the future, while joining together to thwart the FBI when they discover that several members of the group are under surveillance. Meanwhile, Liz begins exhibiting even more alien-like powers, that cause her to see visions of their future - including their deaths.