In the series opener, after 47 refugees mysteriously wash up in a small fishing town, local sheriff Jude Ellis teams with DHS agent Emma Ren to assess their unusual claim that they're fleeing a war 180 years in the future.
In a flash-forward to the year 2187, Reece finds Leah, an orphaned Common baby, and goes against her Apex cohorts to take her in as her own. In present day, Jude - hoping for a peaceful solution with the Feds - is blindsided by a mysterious black-ops team's intent on capturing Reece by any means necessary.
A wounded Reece faces off with her pursuers miles away, while Jude's plan to spend quality time with his son leads to a terrifying ordeal. Back at the camp, Hannah escapes to get her first look at the outside world as Dr. Sophie Forbin arrives to assess the larger threat presented by Leah's unusual virus. Meanwhile, Emma discovers unsettling information which makes her question who she's really working for.
Desperate to rescue his son, Oliver, from a potentially lethal situation, Jude reaches out to Emma with a request that could endanger the lives of everyone at the camp. Meanwhile, Hannah's secret past comes to light, Sophie discovers something unexpected in Leah's blood work and Paul discloses a shocking piece of information about the earlier migration.
Flashbacks reveal a haunting connection between Marshall and the early migration. Meanwhile, Jude investigates a mysterious disappearance, and Sophie risks her life and career to help Reece save her daughter.
Jude is forced to confront his past when he travels back to Oakland to seek assistance from a former colleague. Meanwhile, Caleb reaches out to Marshall after noticing heightened security around the camp; and Sophie experiences an unexpected setback with her plan to help Reece reunite with her daughter.
As tensions in the camp rise, Craig Lindauer agrees to allow a select group of refugees take a trip into town, causing Jude to question the sudden show of goodwill. Meanwhile, Hannah shares startling information with Marshall, and Caleb discovers that a survivor amongst them is an Apex insider.
A grisly discovery in camp leads to the arrest of an unlikely suspect, and a risky move by Jude may be the only way to expose the truth. Meanwhile, Reece finds herself captive, and Rebecca falls under the sway of Naomi in a way that could change everything.
A local homeless woman's surprising connection to the crossing provides Jude and Nestor with crucial answers about what really happened at the threshold. Meanwhile, Naomi's growing influence at the camp leads to a shocking confrontation.
Jude and Nestor form a plan to break the refugees out of the camp, but it's complicated when Sophie arrives with information on Reece's whereabouts. Not content to wait, Marshall takes matters into his own hands.
The lives of the refugees hang in the balance as Jude and Nestor team up with an unlikely ally. Meanwhile, Eve and Lindauer move forward with their ruthless effort to tie up loose ends. Series Finale.