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

Duplicate versions of Michael, Isabel and Tess come to Roswell after killing their king Zan, to urge Max to attend an important interstellar summit in New York City, but they have their own agenda; Ava stays behind in Roswell.

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.

Max witnesses a tragedy and is haunted by the ghost of a man he could have saved, leaving him overwhelmed with guilt and questioning his healing abilities. Isabel aka the Christmas Nazi (dubbed by Michael) tries to brighten up the holiday season and Tess tries to became a part of the Valenti family.

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.

Brody Davis, his mind frazzled from an electric shock,holds several members of the gang hostage, when he begins to remember what happened when he was abducted, such as the New York City interstellar summit and the fact that Max is an alien. Max must use his healing abilities to fix Brody's mind so that he doesn't remember the alien mind that inhabits him. Tess must mindwarp Amy DeLuca into not remembering that Brody held them hostage.