Michael discovers the hidden history behind the 1947 crash when interviewing a World War II survivor for a school project. The story unfolds with familiar faces portraying people in 1947.

The Skins make all the humans in Roswell, New Mexico disappear turning it into a ghost town.

Sheriff Valenti is suspended from the force after refusing to answer the FBI's questions about Max and Isabel, but he soon finds himself right back in the thick of things when Laurie DuPree shows up at his house claiming to be chased by aliens.

When the gang makes a spur-of-the-moment trip to Las Vegas, in order to spend the DuPree money, the event-filled excursion ends in a faceoff between Max and Michael over leadership; Tess and Liz can't pass for over-21-year-olds; Maria recruits Alex to help her audition for a role that ends up to be for a stripper; Isabel meets a man.

Liz continues her investigation into Alex's death while Isabel plans her future and Maria wonders whether Michael will always be around.

When the gang attempts to return to their normal lives, they soon find that their lives have gotten a lot more complicated, which includes Jesse attempting to come to terms with his newfound knowledge but matters are complicated when he finds himself under FBI scrutiny, and Max's "death" creates a unique situation within the alien authority structure, resulting in a new King...Michael.