Liz Ortecho reluctantly returns to her tourist-trap hometown of Roswell, N.M., and reconnects with Max Evans, her teenage crush who is now a Roswell police officer. But Liz soon discovers a shocking truth: Max is an alien who has kept his unearthly abilities hidden his entire life, along with those of his otherworldly sister, Isobel, and their friend Michael. Elsewhere, Master Sgt. Jesse Manes spearheads a long-standing government conspiracy—unbeknownst to his son, Alex Manes.

The anniversary of Rosa’s death reignites tensions as the town takes aim at Liz and her father, Auturo, for what happened on that fateful day 10 years ago. Meanwhile, Max confronts Michael and Isobel, who are concerned that his feelings for Liz will expose their secret. Elsewhere, Master Sergeant Manes’ attempt to convince Kyle of the alien conspiracy in Roswell takes an unexpected turn. Finally, Liz and Kyle make a shocking revelation about Rosa’s death.

After uncovering some unsettling information about Max, Liz runs a series of tests to see what his powers may be capable of. Michael and Isobel take matters into their own hands after learning that Liz may be getting too close to Max. Liz enlists Maria’s help as she goes on a scavenger hunt across Roswell to uncover more about Rosa’s final days.

Fearing that his identity will be uncovered, Max is conflicted when a town-wide power outage leaves patients at the hospital in need of help. Meanwhile, Liz turns to Kyle after learning details about the night Rosa died. Elsewhere, Isobel and Michael come up with a plan to deal with Liz, and Master Sargent Manes seeks help from an unlikely source.

Max and Michael begin to worry about Isobel after a series of mysterious blackouts cause her to spiral. Liz turns to Grant Green for help when she learns that he may have witnessed something strange on the night Rosa died. Meanwhile, Kyle and Alex uncover a secret that Kyle’s father had been keeping from everyone.

In a series of flashbacks to 2008, secrets are uncovered about Rosa’s final day, Isobel’s mysterious blackouts and Alex and Michael’s relationship in high school.