Julia, a 14-year old orphan, is placed in the care of foster parent Mr. Leopold where she joins his other charges, Johnny, Tabby and Finn, on a 2000-acre farm. But when an Alien's ship crashes into their barn they learn Julia is not the only new arrival.
The escaped endlings on the Leopold farm put the family at odds, leaving Julia's future there in question. But after one of the creatures allows Julia to relive her past, it's up to her to decide whether or not she'll let her past control her future.
Another endling's escape wakes the injured Alien. With the police and a mysterious guest on their way, Tabby and Julia argue over what to do with their now-awake visitor, while Johnny worries about another run-in with law enforcement.
With Julia and Finn on the run with the Alien, it's up to Johnny, Mr. Leopold and a reluctant Tabby to find them. What they don't know is that while Julia is trying to get away from the farm, a subterranean creature is being lured there.
After Tuko's caretaker Abiona takes revenge on the Alien, Julia must find a way to convince her to help. Unfortunately, the Alien isn't the only being who needs saving as Johnny, Tabby and Finn deal with a new endling, this one from earth's own history.
The pursuit of a mysterious new creature catches the attention of the local police. After a particularly close encounter, Mr. Leopold forbids Johnny from continuing the chase, causing a rift between foster father and son.
Tabby has a disappointing visit with her estranged mother while Julia, Johnny and Finn try to save an adorable endling. When Tabby falls in love with the new creature and tries to hide it, her feelings threaten the safety of her foster family.
Abiona joins Johnny and Julia's search for a new sightless endling, while back at the farm Tabby tries to keep Finn and Mr. Leopold from discovering the creature she's hiding in the house.
While Mr. Leopold confronts his past, Johnny, Julia, Tabby, and Finn must trap a recently released endling before it traps them.
With the recently named Alien on the mend Julia, Johnny, Tabby and Finn turn their attention to helping a new endling that can't survive in the cold. But the creature's unique ability to hide makes saving it nearly impossible.
While pursuing an elusive endling, Julia, Johnny, Tabby and Finn come across a menacing trap and realize they're not the only ones trying to capture the creature.
Tabby, Johnny, Julia and Finn race to save a trapped endling while a seemingly endless stream of drones try to capture it. Unhappy with her drones' progress, Hewes and her team arrive to finish the mission themselves.