Episode 1: Disguise and Crisis
Harry (played by Alan Tudyk), an alien assassin, crashes his spaceship on Earth. To complete his mission of eradicating humanity, he kills Harry Vanderspeigle, a reclusive local doctor, and assumes the doctor’s identity through molecular reconstruction. Four months later, he hides in a remote town in Colorado, trying to recover the lost destruction device.
When Sam, the town’s only other doctor, dies under mysterious circumstances, Harry is asked by the police to perform an autopsy. He barely navigates human society using English and driving skills learned from TV, but his behavior is highly odd—playing with the victim's brain during the autopsy, using his "sense of smell" to determine the time of death, and even making excited "chung-chung" noises at the corpse.
Max, a 9-year-old boy, accidentally sees through Harry’s alien identity. He screams "There’s an alien under the bed!" and flees, putting Harry in a crisis of needing to silence him. Harry sneaks into Max’s room to kill the boy, but is forced to hide under the bed when Max’s parents suddenly enter—his perfect disguise first shows a crack.
Asta (played by Sara Tomko), a female nurse, insists Sam was murdered and convinces Harry to reinvestigate. Together, they find clues suggesting Sam might have been poisoned. Forced to cooperate with Asta, Harry gradually develops a subtle empathy for humans: he comforts Asta after she is hurt by her ex-husband’s harassment, and even dances awkwardly with locals at a bar after getting drunk, briefly experiencing the warmth of human emotions.
However, Max’s persistent threat and the countdown to his mission (he must find the device before the snow melts) still weigh on him. Staring at the wreckage of his spaceship by the lake, Harry whispers, "Are humans worth saving?"
Episode 2: Awakening Humanity and Identity Crisis
Harry officially takes on the role of the town’s clinic doctor. On his first day seeing patients, he runs into Max—who jumps out the window and flees. Harry’s threat, "I’ll cut your head open," is heard by everyone present.
Sheriff Mike (played by Corey Reynolds) scoffs at Max’s "alien accusation," but Deputy Liv (played by Elizabeth Bowen) draws a portrait of the alien based on Max’s description and posts "wanted posters" all over town.
Harry makes a series of jokes at the clinic: mistaking a gynecological exam for a "wart check," referring to women’s breasts as "tits," and even poking a baby’s stomach with a cane to find its "laugh spot" during a checkup. He crams medical knowledge through the internet, but is left speechless when Asta asks about his background—only able to say, "I’m just… hungry." In reality, he is overcome with "homesickness" for his home planet.
Asta discovers that Sam’s prescription pads were still being used after his death, leading her to suspect the killer is someone inside the clinic. Harry pretends to be a mailman and calls Max, trying to trick him with the lie "The alien has left town," but is exposed when he incorrectly guesses the stamp price (saying $100 instead of the actual $30). The two bicker over the phone, calling each other "idiot" and "moron"—their childish confrontation hides Harry’s fear of failing his mission.
That night, Harry confides in Darcy (played by Alice Wetterlund), an astrophysicist, at a bowling alley: "Human emotions are a weakness, but they’re also their greatest strength."
Asta learns that Sam helped arrange the adoption of her daughter (whom she gave up years ago), and the adoptive family lives in the town. Harry witnesses her sorrow and offers to play cards with her to comfort her—even though he is confused by humans being "controlled by emotions."
Meanwhile, Harry receives a message from his home planet, reminding him "Mission comes first." At the same time, Max and his new ally Sahar (played by Millauna J. Kelley) plan to break into Harry’s cabin to find evidence, escalating the crisis on both fronts.
Episode 3: The Corpse’s Secret and Alien Threat
A fisherman finds a severed foot in the lake; DNA testing reveals it belongs to the real Dr. Harry. Harry sneaks out at night to fish the real Harry’s body out of the lake, hides it in a basement freezer, and covers it with frozen meat. However, Asta catches him moving the body, so he lies and claims it is his "twin brother."
Sheriff Mike launches an investigation targeting a "serial killer," forcing Harry to forge evidence—he uses foreskin from a baby’s circumcision to replace the severed foot’s DNA sample, barely getting away with it.
Max and Sahar break into Harry’s cabin, accidentally triggering the alarm. Harry quickly transforms into his alien form to scare the kids away. Through his cooperation with Asta, he gradually understands human emotions: when Asta breaks down after learning her daughter might be abused, he awkwardly pats her hair in an attempt to comfort her.
Abigail (played by Jenna Lamia), Sam’s wife, storms into the clinic to fight for his belongings. Harry watches coldly as humans act crazily for "someone they love," but secretly admits, "This kind of devotion might be worthy of respect."
The police search Harry’s cabin. When the freezer is opened, viewers’ hearts stop—yet the sheriff only notices the bison steaks inside; the body has been moved by Harry in advance, allowing him to escape suspicion. During the crisis, Harry reveals his alien abilities: catching a bullet with his bare hand and healing wounds instantly—but he pretends to be a "lucky human" in front of Asta.
Asta discovers that Sam was involved in her daughter’s adoption process. By the lake, Harry encounters two mysterious aliens—they are "cleaners" sent by his home planet, who have found the spaceship wreckage and are ready to activate the device. Looking at the human town in the distance, Harry makes his first clear choice: "I’m going to protect them."
At the same time, with Sahar’s support, Max mails a drawing of Harry’s alien form to the FBI—unleashing the show’s biggest cliffhanger.
