The Vohrsoth were genetically engineered species created by an extinct civilization. They sought to gain dominance over the galaxy through improving themselves by adding the DNA of other species to themselves.
The Vohrsoth inhabited a space station known as "The Forge". To gain samples of other species the Vohrsoth launched probes that would engage any starship they met. If the starship was able to destroy the probe it would trigger a trap, which would transport the vessel to the station where it would be trapped by the dampening field so its crew could be 'harvested'.