After their two teenage children exhibit mutant powers and are targeted by the government's Sentinel Services, the Strucker family are forced to go on the run -- and turn to the mutant underground for help.
Blink goes into a state of shock, creating a portal that puts the mutant underground at risk. As Caitlin and Eclipse go in search of medication to save her life, a captive Reed finds himself at the mercy of Sentinel Services. Polaris runs into trouble inside the prison.
Reed cuts a deal with Sentinel Services, who plan to use him to track the location of the mutant underground. Meanwhile Caitlin and her kids turns to relatives for help, and Thunderbird tries to train Blink how to control her powers without fear.
The mutants hatch a risky plan to free their friends by intercepting a Sentinel Services prisoner transport, forcing Eclipse to turn to a former lover for intel. While Lauren and Andy try to help the cause with their combined powers, Blink experiences memories that are not her own.
Haunted by the memories of his past, Jace throws all of the resources of Sentinel Services into tightening the noose around the mutant escapees. Meanwhile Reed must prove his usefulness after clashing with members of the underground.
The mutants plan to break into a federal building to gain more intel on Sentinel Services and its use of mutants turned against their own kind, putting Andy into the field with his dad. While Lauren makes a new friend, Blink decides to leave the group.
Eclipse is pressed into service of the cartel after receiving a call from his former lover, Carmen, but Lorna grows suspicious. Thunderbird finds Blink and helps her to locate the foster home where she used to live, and Reed discovers that Lauren's new friend has a checkered past.
The mutant underground is finds itself with a prisoner after a mutant conditioned by Sentinel Services tries to infiltrate their ranks amidst a group of refugees. Meanwhile Reed goes to speak with his estranged father, discovering his family's unsettling secrets.
Thunderbird and telepathic newcomer Esme push the team toward a risky plan to free mutants who are being held by Sentinel Services. The Struckers consider their kids' future after Andy and Lauren discover the power of their bond.
After their children are captured Reed and Kate are convinced to appeal directly to Agent Turner, as the mutants plan to attack Sentinel Services directly to rescue their friends -- unaware that they are being manipulated for someone else's hidden agenda.
As both sides mourn their dead the Struckers debate whether to remain at Mutant HQ, and Esme and her sisters propose an alliance with the mutant underground to take down Sentinel Services. Elsewhere, Dr. Campbell tries to regroup and regain Agent Turner's trust.
When Dr. Campbell seeks to fund his research at the controversial Humanity Today conference, the mutants agree to join forces with Esme and her sisters to infiltrate the event and capture him. Believing that Sentinel Services may be looking for his mother, Reed takes the family to try and convince her to go into hiding.
Turner and Sentinel Services corners the mutant underground headquarters, forcing Reed and Caitlin to lead a desperate escape plan to escape from the siege. Marcos rushes to try and stop Lorna from an act that will change her forever.
