The crew of HMAS Hammersley. Hammersley intercepts a Foreign Fishing Vessel (FFV) and, after forcing the FFV to stop, boards it and discovers some Asian fishermen. ET and Jaffah remain on the FFV while it is towed back to base by Hammersley.
Hammersley answers a distress call from a marine biologist on Bright Island, and they release the FFV. The distress call becomes a medical emergency and the crew discover that a young woman scientist has been poisoned and Swain, the boat's medical officer, is forced to perform a tracheotomy on her. Shortly after, the woman is taken to Hammersley. Despite the attempts at resuscitation by Swain and Hammersley's 2IC and executive officer, Lieutenant Kate "XO" McGregor, the woman dies.
The crew of the FFV accidentally set their vessel alight and its crew, with Jaffah and ET, are forced to abandon ship. They begin to fear Hammersley will not find them.
When Hammersley arrives back at base, the CO discovers that the Australian Federal Police (AFP) are very interested in the death of the marine biologist, Lisa Holmes. When Holmes' colleague, Doctor Ursula Morelle, arrives to identify the body, it appears that she is not disclosing something. Despite this, the captain becomes romantically interested in the doctor. The CO becomes very interested in Bright Island.