Liz Parker learns Max Evans' out-of-this-world secret when he saves her life and must rely on her to safeguard his secret as an orphaned extraterrestrial.
Liz tries to maintain her relationship with Kyle despite her deep bond with Max; Michael is obsessed with the idea that there was another alien in Roswell in 1959 and tries to decipher the meaning of the flashes only he sees. Meanwhile, Liz suspects the new guidance counselor Ms. Topolsky is hiding something, especially when she sees her with Michael's file.
Isabel is concerned about Maria's nervous reactions to Sheriff Valenti, so she invades one of Maria's dreams to determine whether she can keep the aliens' secret.
Liz's grandmother is rushed to the hospital after suffering a stroke prompting Liz to reach out to Max for comfort.
Liz discovers her personal journal, which contains all she knows about the aliens, is missing and she fears it has fallen into the hands of someone who could expose the aliens.
Micahel's monomaniacal urge to find the geodesic dome that's been stalking his dreams leads him to hijack Maria's car to Texas.
Liz and Max journey to an American Indian reservation where they glean information from an elderly tribesman about the alien who vanished in 1959.
Max is injured in a car accident and Liz pressures Alex to help protect him from medical procedures that could expose his identity by providing blood samples to replace Max's.
A freak December heat wave hits the town and sparks romance as Michael's relationship with Maria heats up and Liz's infatuation with Max intensifies; meanwhile Isabel enters into one of Alex's dreams only to discover her likeness already there and dancing with Alex.
While at the reservation Micael ends up in an alarming hallucinatory state and the others must band together to save his life.
When Max rescues his mother from a kitchen fire she faces her suspicions about his extraordinary abilities; Liz reaches out to Kyle in friendship.
A new UFO sighting sends suspicion and fear through the town and leads Max and Isabel to investigate the incident during a school camping trip.
Max plays host to actor Jonathan Frakes at the annual UFO Convention while trying to avoid the meddlesome couple who witnessed Max's life-saving abilities on Liz at the Crashdown Cafe.
Maria enters Liz in a blind date contest; Max and Kyle commiserate about their shared feelings for Liz; Michael and Isabel send a signal to the fourth alien.
After Michael has a violent showdown with his father, Max and Isabel's father helps Michael set up his emancipation; the fourth alien emerges as a shapeshifter who watches over Max, Michael and Isabel.
Liz is unnerved by her strong desire for Max and the visions that come when they kiss - visions that lead to a glowing orb in the desert.
FBI agent Topolsky returns to warn Liz that a covert alien hunter inside the Bureau is pursuing Max and his friends -- and that he will stop at nothing to get what he wants. Meanwhile, Isabel befriends Tess, a new female student who immediately arouses Max and Michael's suspicions.
Max develops an uncontrollable attraction to Tess that includes intense sexual daydreams, and Sheriff Valenti learns that Topolsky was killed in a suspicious fire. Meanwhile, someone has secretly placed a video camera inside Michael's apartment.
Harding finds the video camera hidden in his house and gives it to Valenti. The lawman then tells Max that his safety depends upon his willingness to share information. Meanwhile, Tess reveals a personal secret to Isabel.
Tess's book suggests that she and Max are predetermined mates, as are Michael and Isabel, who thinks she might be pregnant -- with Michael's baby. Meanwhile, Nasedo disguises himself as Max and kidnaps Liz as part of a plan to trap FBI agent Pierce.
Max finds himself in a white room with no windows or doors, facing questions by Agent Pierce. Isabel telepathically contacts Max, who leaves her clues to his location. Michael, Isabel and Tess then set out on a rescue mission.
After escaping from Pierce, the aliens save Nasedo. Michael accidentally kills Pierce. Nasedo, as the aliens' guardian takes Pierce's place to help the aliens. The aliens figure out how to use the devices and release a message from Max and Isabel's real mother. She says Max is their leader and Tess, his fiance and that Michael is Second in command and he is Isabel's fiance. After hearing all this Liz runs out.
Max and the others must rescue Michael after he is arrested for murder; Liz takes a job with a congresswoman who has a hidden agenda.
Brody Davis, the mysterious new curator at the UFO Museum has the group on edge, and Michael and Isabel plotting his demise.
Isabel is deeply moved when Max throws her a surprise birthday party, but she grows troubled after seeing visions of a bound and gagged Tess. Alex does an interesting cop striptease for Isabel. Congresswoman Whitaker is revealed as Nasedo's killer and as a Skin.
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.
An older Max travels from the future (2014 to be exact) to tell Liz that their relationship will imperil his planet and together they devise a plan to change the future: by making present Max fall out of love with Liz. Not an easy task until Liz tricks Max into believing she slept with Kyle.
After the death of congresswoman Whitaker, Max and the gang visit her hometown, Copper Summit, Arizona, where they find themselves trapped in enemy territory when they learn the whole town population are Skins.
The Skins make all the humans in Roswell, New Mexico disappear turning it into a ghost town. Their assault ends with the death of one of the aliens: Courtney the helpful Skin. Fortunately Tess uses her mindblowing powers and destroys all the other Skins or so it seems until Max and Tess spy a boy resembling Nicholas on a scooter at the end of the episode.
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.
When Isabel develops a psychic connection to a girl who has been buried alive, she races to find the teenager before it's too late. Meanwhile the FBI comes to town and starts asking questions concerning Valenti and his involvement with Max and Isabel.
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.
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.
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.
The onset of junior prom stirs up emotional tumult as Liz tempts fate by asking Max to be her date, Isabel decides Alex is the man she's been searching for, and Michael tells Maria he won't take her to prom.
The sudden death of a close friend shocks the group.
A startling breakthrough leads to a renewed connection for two of the gang. Differing reactions to a life shattering event creates tension among the gang, resulting in heartfelt revelations, hidden insecurities and thoughts of leaving Roswell. Meanwhile, Liz enlists Sean in her continuing quest for answers into the death of Alex.
Max is hit with a one-two punch after he discovers that not only is Tess pregnant with his son, but that the baby cannot survive unless they return to their home planet. Liz, Maria and Michael work together to unravel the mysterious double life of Alex. Isabel and Kyle explore her powers as they play pranks on Max and Kyle dreamwalks with a Playmate.
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.
Max, Isabel, Michael and Tess struggle with goodbyes on what they believe to be their last night on Earth before they travel back to their home planet. In the final hours, Max frantically searches for the killer that is still out there and threatens the lives of everyone they love.
Max and Liz are arrested and jailed for holding up a convenience store. Meanwhile, Isabel has a secret affair with a handsome attorney, and Michael tries to straighten out his life.
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.
With Alex's ghost as her guide, Isabel must finally confront her fears about love and her conflicted feelings for Jesse. Meanwhile, Maria happily discovers a whole new, human part of Michael in, of all places, a bowling alley, and Liz and Max struggle to remain together despite her father's insistent disapproval.
Max travels to Hollywood while investigating a murder he believes was committed by an alien. He discovers a link to a Paramount science fiction show called "They Are Among Us" and when he goes to the Paramount lot to investigate he ends up auditioning for the part of an alien on an episode of "Enterprise" directed by Star Trek alum, Jonathan Frakes. Meanwhile, back in Roswell, Isabel and Jesse struggle over how to reveal their engagement to their families.
Max, with the help of Kal Langley, undertakes a dangerous journey as he seeks to learn of the fate of Tess and his son. Meanwhile, back in Roswell, Isabel and Jesse must face the negative reactions of their parents and friends to their impending marriage.
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.
After their idyllic wedding, Isabel and Jesse are stalked on their honeymoon by her alien lover Kivar who plots to take her back to their home planet. Learning of this, Max and Michael arrive intent on destroying the alien. Meanwhile, Liz and Maria discover that Philip has begun a secret investigation of Max, including the diappearance of Tess, and he's embroiling Liz's dad into the whole thing.
When an old love visits Maria her passion for music resurfaces, which jeopardizes her relationship with Michael. Meanwhile, while Max's father is still trying to put together all the pieces of his investigation, Isabel joins Max in the quest to stop him.
When Max is fascinated by an intriguing autistic child he wonders if his own lost child is attempting to reach out to him. Meanwhile, Michael plays Santa to Maria and Liz's elves at a charity event. Isabel and Jesse share their first holiday together as husband and wife.
In an attempt to find Roswell's legendary New Year's Rave, Max and Maria join forces. Meanwhile, Liz connects with her father and Isabel helps Kyle find the perfect date for New Year's.
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."
When Liz begins to undergo some strange, alien-like changes to her body, she decides she needs to get as far from Max as she can. In order to separate from him she must leave Roswell to go to boarding school in Vermont. Meanwhile, Maria gets offered a recording contract in New York, but she isn't sure she likes what the record label people are doing to her music to make it "popular."
Michael uncovers a conspiracy at Metachem, when a guard is killed on duty. Michael enlists the aid of Max and Isabel when the investigation takes an alien turn. Meanwhile, Liz has entered boarding school in Vermont and tries to start a new life, and Maria disillusioned by New York goes to visit Liz in Vermont.
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.
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.
Michael witnesses a fatal crash between a fighter jet and an alien vessel, and embarks on his own investigation leading to the recovery of an artifact. Meanwhile, Isabel spends the day with her mother, who's harboring a secret agenda and is working with her husband to discover Max & Isabel's secret, which leads to a shocking revelation.
Max's quest to find his son ends with the return of Tess and the baby, and the gang find themselves in danger again while trying to protect the child. Meanwhile, Jesse encourages Isabel to reveal her true origins to her parents, and the elder Evanses provide a way to ensure their grandchild's safety.
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.
