In the pilot episode, "Caretaker," Voyager is on a mission to locate a missing ship piloted by Maquis fighters. Janeway brings Tom Paris, a former Starfleet officer, out of prison to help find the ship. Maneuvering through the dangerous Badlands, an ancient alien known as the Caretaker transports Voyager to the Delta Quadrant, on the other side of the galaxy, where the Maquis ship was also sent. In the process, several members of Voyager's crew are killed, including the first officer, helmsman, chief engineer, and all medical personnel. Voyager and the Maquis ship are attacked by Kazon raiders intent on capturing the Caretaker's Array, which was used to transport the ships. The Maquis ship collides with a Kazon ship, destroying both, after the Maquis crew transports to Voyager. Believing the Kazon will use the Array to harm the Ocampa, Janeway decides to destroy it rather than use it to return home. The Starfleet and Maquis crews integrate and work together as they begin the 75,000-light-year journey home, predicted to take 75 years. Chakotay, leader of the Maquis group, becomes first officer. B'Elanna Torres, a half-human/half-Klingon Maquis becomes chief engineer. Tuvok is revealed to be a Starfleet spy on the Maquis ship and resumes his duties as chief security officer. Paris becomes the helmsman, and the Emergency Medical Hologram, designed for only short-term use, becomes the chief medical officer. In the Delta Quadrant, the crew gains the Talaxian Neelix as a local guide and chef, along with his Ocampan girlfriend, Kes. Both Paris and Kes become qualified assistants to the Doctor, expanding the ship's medical capabillity. The crew expands to include Seven of Nine, a Borg drone liberated from the collective, in the show's fourth season. The Delta Quadrant is mostly unexplored by the Federation. On the way home, the crew contends with hostile species that include organ-harvesting Vidiians, belligerent Kazon, nomadic Hirogen hunters, the Borg and Species 8472 from fluidic space. They also encounter hazardous natural phenomena.