Port Eternity — C.J. Cherryh

Their names were Lancelot, Elaine, Percivale, Gawain, Modred, Lynette and Vivien, but they were not characters from legend: They were made people, clone servants designed to suit the fancy of their opulent owner, the Lady Dela Kim. And they worked aboard the Maid, an anachronistic fantasy of a spaceship, decorated with swords, heraldic banners, old-looking beams masking the structural joinings, and lamps that mimicked live flame.

They lived in a kind of dream, and had no idea of their origins, their prototypes in those old, old story tapes of romance, chivalry, heroism and betrayal.

Until a wandering instability, a knot in time, a ripple in the between sucked them into a spatial no-man's-land from where there seemed to be no escape. And they were left alone, with the borrowed personas of their ancient namesakes, to face a crisis those venerable spirits were never designed to master!