Renegade Starfleet Captain Maxwell of the U.S.S. Phoenix is attacking the Cardassians, and the Enterprise must intercept and stop him before he starts a war.

Bob Gunton (Captain Ben Maxwell)
Rosalind Chao (Keiko O'Brien)
Marc Alaimo (Gul Macet)
Colm Meaney (Lt. Miles O'Brien)
Marco Rodriguez (Glinn Telle)
Time Winters (Glinn Daro)
John Hancock (Admiral Haden)

• This episode introduces the Cardassians, who would later be seen in "Ensign Ro" and "Chain of Command, Part I", along with being important figures in the history of Deep Space Nine. On the star charts, the Cardassian Union is located "west" of the Federation, opposite from the Klingon and Romulan Empires. A treaty was signed one year ago, which ended the hostilities between the Cardassians and the Federation. Maxwell discovered that the Cardassians are secretly rearming for war.
  
• The U.S.S. Phoenix NCC-65420 is a Nebula-class starship. This is the first appearance of the Nebula-class starship, which has a similar design to the Galaxy-class starship, in a different configuration.
  
• O'Brien was Maxwell's tactical officer on the U.S.S. Rutledge NCC-57295 during the Federation-Cardassian border conflicts in the 2340's.
  
• Marc Alaimo will go on to play a different Cardassian — Gul Dukat — on Deep Space Nine.
  
• The Cardassian rank Gul is equivalent to Captain, and Glinn is equivalent to Commander.
  
• The song O'Brien and Maxwell sing is "The Minstrel Boy" by Thomas Moore.