With the help of Captain Hernandez, Trip and the newly-launched starship Columbia, Archer pursues the kidnapped Phlox deep into Klingon territory, as Phlox decides to cooperate with finding a cure to a virus ravaging a Klingon outpost. Meanwhile, Archer demands that Reed disclose his secret orders when his ties to a mysterious intelligence organization are revealed. Later, when Trip temporarily returns to Enterprise, T'Pol tries to broach an uncomfortable subject with him.

Kristin Bauer (Laneth)
James Avery (General K'Vagh)
John Schuck (Dr. Antaak)
Terrell Tilford (Marab)
Eric Pierpoint (Agent Harris)
Ada Maris (Captain Erika Hernandez)
Wayne Grace (Admiral Krell)

Matt Jenkins (Columbia Tactical Officer)

• Part 2 of 2.
  
• Phlox finds a cure for the virus, but it leaves 7 million Klingons without ridges, a genetic trait they will pass onto their children. Phlox notes the appearance can be corrected with cosmetic surgery.
  
• The Columbia's registry is NX-02. It is a slightly different color than Enterprise (more silver-grey) and has minor improvements over Enterprise.
  
• T'Pol and Trip have been sharing daydreams. After Hoshi melded with T'Pol, she also had a dream about Trip.
  
• This episode (and the previous) cleverly explain the radical change in Klingon makeup design between The Original Series and The Motion Picture.