A pleasure-loving Delta Quadrant people with a device that could fold space, whose laws forbade them from sharing it to get Voyager home.
The Sikarians are a Delta Quadrant species devoted to pleasure, hospitality and stories, which they value as highly as any physical goods. Their world has a technology called a spatial trajector that can send people across vast distances instantly, enough to cut decades off Voyager's journey.
In the episode Prime Factors, their leader Gath refused to share the technology because Sikarian law prohibited it. Tuvok, B'Elanna Torres, Seska and Joe Carey secretly traded Voyager's library of literature to another Sikarian in exchange for a trajector, but it would not work with Voyager's systems. Captain Janeway, angered by the betrayal, reprimanded the crew members involved.