The Avatar is a 1978 science fiction novel by Poul Anderson. The story combines space opera, political intrigue, and first-contact themes, following a group of human and alien travelers who become lost in the galaxy in search of a mysterious, ancient alien race known as the Others. 
 
The story begins in the not-too-distant future, where an inscrutable alien race called the Others has left "gates" throughout the galaxy, allowing for interstellar travel. While humanity has used these gates to colonize one star system, a repressive government on Earth, the Social Welfare Party, halts all further exploration and seizes the returning starship Emissary and its crew. 
 
Displeased with this isolationist policy, wealthy entrepreneur Daniel Brodersen commandeers his own ship to rescue the imprisoned crew and a visiting Betan alien. His plan goes awry, and he and his companions—including his lover, Caitlín Mulryan—end up hopelessly lost in uncharted space. Their only hope for a return to Earth is to find and make contact with the elusive Others.