After making a miraculous recovery, Chris Smith aka Peacemaker returns home after four years locked up in Belle Reve, but soon discovers that his freedom comes with a price. It seems that Amanda Waller is not quite done with him yet.

After Peacemaker's hazardous escape, the team think that someone is leaking information about Project Butterfly, causing mistrust and strife within the group. Back at home, Peacemaker has a moment of doubt that is interrupted by the arrival of Vigilante/Adrian Chase.

On their first official mission to assassinate suspected "butterflies", Economos and Murn bond, and Peacemaker and Harcourt reach an understanding. But the job goes sideways thanks to the arrival of the small but lethal Judomaster, and Peacemaker's newfound conscience.

After their somewhat successful mission, Murn decides to make Vigilante a part of the team to keep him close. Meanwhile, Peacemaker stocks up on 'supplies' at his dad's house, only to learn that his ultra-racist father is now mistakenly in prison thanks to the team.

The team scouts the apparent hub for the aliens' food supply, only to come face-to-face with a full-fledged invasion. Meanwhile, Auggie sells out his son to Det. Song and Fitzgibbon, but they have trouble making the charges stick due to Murn's mysterious contact.

After Adebayo's surprise, Murn reveals his greatest secret. Sprung from jail by Detective Song, Auggie Smith returns home with plans to kill his son. Meanwhile, the police's botched arrest of Peacemaker sends alien Goff into an unexpected new host.

While White Dragon and his army set their sights on hunting down Peacemaker, he and Vigilante set out to kill the aliens' "cow". Meanwhile, Harcourt and Murn confront Adebayo about her betrayal, but all three are soon surrounded by a full battalion of "butterfly" cops.

It's Team Peacemaker vs. the Butterfly invasion! With Peacemaker and Adebayo at odds, can the team kill the "cow" once and for all? Or, will their fracture give the aliens the opening they need to complete its teleportation?

Tetsu arouses concern at Shinsengumi headquarters when he refuses to get out of bed.

Souji causes a commotion at headquarters when he steals Hijikata's collection of haikus.

Tatsu barely survives another encounter with Sakamoto; a man poses as Souji.

Hijikata and Souji pursue a imposter, but their search leads them straight to the gates of death.

Concern over Ayumu's absence continues to grow at Shinsengumi headquarters.

Reports of a woman being beaten by a group of samurai send the Shinsengumi flying into action.

Souji and his men set out on a quest for vengeance after the murder of their comrade.

As the Shinsengumi prepare for all-out war, Yamanami struggles with painful flashbacks.

The bloodshed is great as the Shinsengumi cut down their enemies one by one; Tetus joins the fight.