Torn between the heartache of Max's sacrifice and the joy of Rosa's resurrection, Liz suppresses her grief to focus on moving out of Roswell with Rosa. Meanwhile, Michael copes with Max's death in his own self-destructive way, while Isobel focuses her attention on honing her alien powers. Finally, Liz makes an alarming discovery after Rosa begins experiencing mysterious side effects from her resurrection.
Liz is forced to put her latest experiment on hold after Rosa begins to struggle with her new life in Roswell. Reluctant to face the truth about his mother's past, Michael turns his attention to helping Maria, who is dealing with her own family crisis. Elsewhere, Isobel agrees to join her mother for a day of spiritual healing to keep herself distracted. Finally, Rosa turns to Kyle to learn the truth about what really happened the night she died.
Determined to regain control of her life in the aftermath of Noah's death, Isobel makes a risky choice despite its potential consequences. Meanwhile, Alex and Michael work together to unravel the mystery surrounding the night Nora's spaceship crashed in 1947. Elsewhere, Liz makes a surprising confession when Cameron shows up looking for answers about Max.
On the verge of a breakthrough in her quest to save Max, Liz turns to Kyle for one last favor that could potentially land him in hot water. Meanwhile, Michael and Alex's investigation into Nora leads them to a farm, where they meet a historian named Forrest. Elsewhere, Cameron confronts Jesse Manes about her sister's whereabouts, and Isobel uses her powers for good.
The discovery of some complications with Max's pod forces Liz, Michael and Isobel to confront the possibility that they may not be able to save him. Elsewhere, Maria and Alex make amends.
Maria's investigation into her mother's disappearance leads her and Alex to the home of a mysterious boot maker named Travis. Meanwhile, on her journey of self-discovery, Isobel's night out leads her into the arms of someone unexpected. Finally, after making some major scientific strides, Liz is dealt a devastating blow.
Liz is forced to revisit a painful part of her past when her mother Helena shows up at the diner unexpectedly. Michael urges Maria to seek help after she experiences a strange vision, and Kyle's attempt to get Steph to open up doesn't go as planned. Finally, Helena's arrival in Roswell sends Rosa spiraling.
Despite promising Liz that he'll take things easy with his new heart, Max sets out to find Cameron after learning that she's gone missing. Michael grows concerned about Maria after a surprising discovery about her family history leaves her vulnerable. Alex goes on a date with Forrest. Rosa makes a decision about her future.
After uncovering a surprising connection to their past, Michael and Isobel learn the painful truth about the night Tripp attacked their mothers. Meanwhile, Alex confronts his father about their troubled family history. Elsewhere, Kyle's first date with Steph takes an awkward turn after Liz inadvertently becomes a third wheel.
After uncovering a cryptic message from the past, Alex, Isobel, Max, Michael and Maria set out in search of answers at the reservation where Alex's mother grew up. Meanwhile, Cameron encourages Liz to reach out to someone from her past after Auturo gets detained.
Driven by the prospects of her scientific research, Liz opens up to Diego about all the good her findings could do. Meanwhile, Max enlists Kyle's help getting to the bottom of the recent abductions, while Michael does his own investigating into Alex's disappearance. Elsewhere, after learning more about her mother Louise, Isobel pays a visit to Rosa, in hopes that Rosa could help her begin to heal.
As the town prepares for CrashCon, Liz and Max attempt to piece together who may be behind a potentially deadly plan targeting the festival. Elsewhere, Maria and Isobel take drastic measure to learn more about the night Mimi disappeared, while Michael is forced to do someone else's bidding.
Having realized that a deadly threat has infiltrated CrashCon, the busiest event of the year, Liz realizes that she can't save everyone she loves - and with Max facing immediate danger, she and Isobel must make a heart-wrenching choice. Meanwhile, Michael finds himself caught up in the conflict between Jesse and Alex once again, even as Maria's life hangs in the balance elsewhere, and Kyle faces a moral dilemma when the enemy requires medical attention.