Archer receives a surprise visit from Daniels, the mysterious time traveling operative who has aided him in the past. Daniels tells Archer that three Xindi-Reptilians have somehow traveled back in time 150 years to Detroit, Michigan. He wants to send Archer and T'Pol back in time to investigate. He also gives Archer temporal tags to bring back anything that doesn't belong in the 21st century. After disguising themselves in clothing from the proper time period, Archer and T'Pol successfully travel 150 years in the past, arriving at night on a Detroit city street in the year 2004.

Leland Orser (Loomis)
Matt Winston (Daniels)
Jeffrey Dean Morgan (Xindi-Reptilian Damron)

Michael Childers (Strode)
Donna DuPlantier (Prostitute #2)
Billy Mayo (Officer #1)
Dan Warner (Officer #2)
Erin Cummings (Prostitute #1)

• The Xindi are creating a bio-weapon using blood samples provided by Loomis' victims.
  
• This episode was rated TV-14 due to the prostitutes.
  
• There are several references to the 1978 motion picture Halloween, including the title named for director John Carpenter; Loomis named after Dr. Loomis, and Strode named after Laurie Strode.
  
• Mayweather, Phlox, and Sato do not appear in this episode; Reed is only heard via communicator, not on-screen.
  
• Leland Orser (Loomis) was previously seen in the DS9 episodes "Sanctuary" and "The Die Is Cast" and the Voyager episode "Revulsion".
  
• Jeffrey Dean Morgan (Damron) later stated he was miserable playing the Xindi-Reptilian because of the make-up and nearly quit acting because of it. He'll later go on to play bigger parts in other series such as Grey's Anatomy and Supernatural, and Negan on The Walking Dead.