As they approach the heart of dangerous Borg territory, the Voyager crew witnesses the near decimation of a Borg armada by mysterious alien lifeforms the Borg call "Species 8472," which is impervious to both Borg and Starfleet technology. When Kim and Chakotay lead an Away Team inside the heavily damaged Borg cube, they are able to investigate the alien lifeform's bio-ship. Moments before they are transported out, Kim is viciously attacked by the mysterious organic-looking alien. As he lies in Sickbay, contaminated with alien cells and transforming into an alien being, Kes has terrorizing premonitions about the new enemy and Janeway realizes it's no longer the Borg they must be worried about.

John Rhys-Davies (Leonardo Da Vinci)

• 3rd Season Finale/Cliffhanger.
  
• Captain Janeway takes painting lessons from Leonardo Da Vinci in the holodeck.
  
• The Doctor modified some of the Borg's nanoprobes used in assimilation to attack the alien cells.