Picard finds himself transported to an alternate timeline in the year 2400 where his longtime nemesis, Q, has orchestrated one final "trial." Picard searches for his trusted crew as he attempts to find the cause of this dystopian future.

Patrick Stewart (Admiral Jean-Luc Picard)
Alison Pill (Dr. Agnes Jurati)
Jeri Ryan (Seven of Nine)
Michelle Hurd (Commander Raffi Musiker)
Evan Evagora (Cadet Elnor)
Santiago Cabrera (Captain Cristóbal Rios)

John de Lancie (Q)

Annie Wersching (Borg Queen)
Jon Jon Briones (First Magistrate)
Patton Oswalt (Spot 73)

Toni Belafonte (Zilah)
Alex Diehl (Harvey)
Paula Andrea Placido (Palace Soldier)
Hanna-Lee Sakakibara (Romulan Rebel)

• In this timeline, the Confederation of Earth has conquered and destroyed other worlds in order to secure a "safe galaxy" for humankind.
  
• Picard is a General in the Confederation; Seven of Nine (Annika Hansen) is the President of Earth. Colonel Rios is back in La Sirena on the Vulcan frontline. Elnor is a dissident and Raffi is hunting down dissidents and aliens. Dr. Jurati is in a lab, experimenting on a Borg Queen.
  
• The Borg Queen is aware that the timeline has been corrupted. According to her, Q made a single change in Los Angeles in 2024, and they need to go to the past and find a "watcher."
  
• In Picard's trophy room, he has several skulls on display, including those of Gul Dukat, General Martok, and Sarek.
  
• Jon Jon Briones (Magistrate) is the father of Isa Briones (Soji).
  
• This episode debuted simultaneously with the Discovery episode "Species Ten-C".
  
• Annie Wersching (Borg Queen) previously appeared on the Enterprise episode "Oasis", which was her first television acting job.