Silent Enemy

Main

 * Jonathan Archer
 * Travis Mayweather
 * Phlox
 * Hoshi Sato
 * T'Pol
 * Charles Tucker III

Others

 * Eddie
 * Mark Latrelle
 * Mary Reed
 * Stuart Reed
 * Madeline Reed

Starships
Enterprise NX-01

Species

 * Kovaalan
 * Human
 * Vulcan
 * Denobulan

States and Organisations

 * Earth Starfleet

Information
The mysterious ship from this episode was later reused as a Kovaalan vessel in a season three episode E².
 * ''As nothing has stated that the ships are not of the same origin I have listed the Kovaalans in the species section above.