The USS Darwin was part of the original task force sent into the Ithassa Region to establish the Starfleet Presence. Primarily a transport, equipment and supply vessel, its first survey mission into the Ithassa landed the Darwin in the Igloo Cluster where it encountered the Grendellai, whom is believed to have hijacked the Darwin.
When the USS Independence was sent to join the Darwin on its survey mission, it found the ship in the hands of a Romulan Warbird crew, although later it was determined the Darwin that the Romulans had landed on could very well have been a dupe.
The final fate of the actual USS Darwin was never determined, whether the ship found was the actual ship and destroyed, or if either the Romulans or Grendellai had stolen the actual Darwin and used a mock-up, when video surveillance showed a complete twist:
An unknown creature that could not be defined was shown attacking the Darwin's captain, A'Ha. Also detected was an unusual cloaking field within the vicinity, however it was never determined what it was-