The Collector Ship is a Collector cruiser damaged by Turian patrols and located by Cerberus.
Shepard is sent to the cruiser to determine how to reach the Collector Base, roughly five missions after he is sent to Horizon. On the ship, he can choose one new weapon talent. He can learn to use Assault Rifles, Shotguns or Sniper Rifles, or gain an upgraded version of one of these if he already has the required talent. Once he has left the ship, he cannot return to it.