The Mutant Underground rescues a girl from a Sentinel raid, but fails to save her family; Eclipse and Caitlin get info on the Inner Circle with help from a criminal hacker; Polaris prepares for her baby's birth.
Thunderbird hopes a mutant lawyer who recruited him to the Underground can help find the Inner Circle; Andy and Lauren have a shared dream; Reed must keep a secret from the group; Jace is back on the mutants' trail.
As Caitlin and Thunderbird struggle to save the life of a mutant injured in the Inner Circle's chaotic liberation of a psychiatric hospital, they discover clues to the identity of the powerful mutant Polaris and Andy were sent to retrieve. Meanwhile, as Jace joins up with the Purifiers to chase down the escaped mutants, he comes dangerously close to colliding once again with the Mutant Underground.
The Inner Circle prepares for a secret ambush, but Polaris is reluctant to join and Reeva tasks Esme with getting Polaris on board. Esme confides in Polaris, revealing her and her sisters' troublesome past. Meanwhile, Thunderbird trains Reed on controlling his powers and The Purifiers attack The Mutant Underground as they attempt to rescue a group of homeless mutants.
Reeva reveals her plans for a major mission for the Inner Circle to secure some needed funds. Meanwhile, the Mutant Underground must contend with Reed's unstable powers, hoping that some medical help from Caitlin and Lauren will keep his destruction in check. Also, Jace is introduced to Benedict Ryan, a well-connected public figure who supports the efforts of the Purifers, but the two may not see eye-to-eye. Then, Thunderbird finally confronts Blink about her dealings with Urg, after weeks of tension over their meeting.
In attempts to stabilize Reed's powers, Reed, Caitlin and Lauren meet with Dr. Risman, a doctor who treats patients with debilitating X genes. However, Lauren finds out Dr. Risman is not who she thought she was. Following the Inner Circle's bank ambush, Thunderbird and Blink continue to work together to chase them down. Meanwhile, Polaris reflects on her troubled relationship with her father and takes steps to protect Dawn from the Inner Circle.
Tensions are rising within the Inner Circle as Andy defends Rebecca against Reeva's treatment. Lauren tries to convince her parents to destroy Dr. Risman's research. A frustrated Jace works with the Purifiers.