Tuvok suddenly begins having strange, disorienting attacks which cause a disturbing childhood memory to resurface. As the trauma begins to degrade his neural system he knows he must take action or he will die. To access and conquer the debilitating memory fragment, he asks Captain Janeway to act as his guide and enter into a mind meld with him. Amazingly, the mind-meld takes Tuvok and Janeway to the scene of the young Vulcan's first Starfleet duty — on the bridge of the U.S.S. Excelsior with Captain Hikaru Sulu in command.

George Takei (Captain Hikaru Sulu)
Grace Lee Whitney (Lt. Commander Janice Rand)
Jeremy Roberts (Lt. Dmitri Valtane)
Boris Krutonog (Excelsior helmsman)
Michael Ansara (Commander Kang)

• This episode, along with the DS9 episode "Trials and Tribble-ations", commemorates the 30th anniversary of Star Trek and marks the first time a cast member from the classic series has appeared on Star Trek: Voyager.
  
• Tuvok served as a junior science offer with a rank of Ensign on the U.S.S. Excelsior NCC-2000.
  
• The episode also contains references back to the feature film Star Trek VI: The Undiscovered Country. In this version of events, Lt. Valtane dies. When Tuvok comes to his aide, he passes a virus to Tuvok. The virus masks itself as a disturbing memory engram, which the brain supresses.
  
• An older Kang was also featured on the Deep Space Nine episode "Blood Oath".