Voyager sets down on a planet for a major maintenance overhaul while away teams in shuttles are sent in search of supplies. Harry Kim, Seven of Nine and Neelix, aboard the Delta Flyer, become caught in the crossfire between Kraylor and Annari ships. The Kraylor captain asks for the Flyer's help as they are on a humanitarian mission, while the Annari continue their attack even after Kim contacts them. Kim orders the others to protect the Kraylor vessel with the Flyer, and cause the Annari to retreat.

Kim and the others transport to the Kraylor ship and find most of the command crew, including the captain, now dead. As they assist the ship's doctor Loken with the other crew, Loken asks for Kim's help to pilot their vessel back to their homeworld with their supply of necessary vaccines as none of the remaining crew have navigation experience and the Annari are still patrolling the sector. Kim agrees, recognizing they will pass near the planet where Voyager has set down, as well as desiring to show his abilities to command a vessel on his own. Kim works at teaching the acting helmsman Terek how to pilot the ship.

They use the ship's unreliable cloaking device to make it to the planet, where they see Voyager interacting with an Annari vessel. After the Annari leave, Kim takes Loken to Captain Janeway to explain the Kraylor's plight. Janeway admits that this leaves them in a difficult position as they have just completed negotiations with the Annari for repair materials, but allows Kim to continue taking the Kraylor home. Kim opts to name the ship Nightingale after the famous wartime nurse. They use the cloaking device to continue to evade the Annari, but the device fails just as they near a fleet of 6 Annari ships. Seven is unable to get the cloak restored, but suddenly Loken gives the crew several instructions for the cloaking device, quickly re-engaging it and allowing Kim to navigate their escape. Kim confronts Loken, who reveals that they are not carrying vaccines but instead are scientists and researchers that created this cloaking technology so they could smuggle supplies to their homeworld through an Annari blockage around their planet. Loken insists that their mission is still humanitarian, but Kim, realizing the severity of the situation, orders the ship to return to Voyager. Loken overrides him and has Terek maintain their heading towards the homeworld. Kim discusses the option of fleeing the ship via escape pods with Seven, but realizes he offered to help the Kraylor and stays onboard to help.

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Wikipedia