Fire Ship by Diane Carey
There's a bar called "The Captain's Table, " where those who have commanded mighty vessels of every shape and era can meet, relax, and share a friendly drink or two with others of their calling. Sometimes a brawl may break out but it's all in the family, more or less. Just remember, the first round of drinks is always paid for with a story...even in the Delta Quadrant.
A sudden attack separates Captain Kathryn Janeway from her ship and crew. Soon she is rescued -- but not by "Voyager." Alone aboard an alien vessel, Janeway finds herself in the middle of a war she cannot yet understand. She must quickly learn the ways of this new culture and work her way back to captain if she is to protect her new allies from the war that only she knows is coming. Without her ship, all her quick wits and Starfleet experience may not be quite enough to save the Delta Quadrant from war.