The Sorceress of Karres — Eric Flint; Dave Freer

As Captain Pausert had often had occasion to observe, life just wasn't fair! Hadn't he (with the help of the notorious witches of Karres), after which, at the least, he deserved some time off. No such luck, though as the Empress herself sent him on a secret mission to stop the nanite plague, but an enemy had somehow convinced the Imperial Fleet that he was actually a wanted criminal, so after a battle leaving his ship in urgent need of repairs all three of them joined an interstellar traveling circus(don't ask!) in order to sve the galaxy once again(as toldf in The Wizard of Karres).

Time for a vacation? Don't be ridiculous-there's a new urgent mission that has Captain Pausert's name on it! This new novel finds the long-suffering Captain and the two young Karres witches-Goth who vows she will marry him when she grows up , and her younger sister The Leewit-being sent off to investigate mysterious and ominous events in the notorious Chaladoor region of space. Goth soon becomes aware that unknown but surely inimical forces are trackingthem, and in order to foil them she takes a desperate route to travel back in time and meet Pausert as a young boy. Meanwhile , the captain and the Leewit find themselves in the middle of their own desperate situation in the Chaladoor.

Whoever it was who said that a change was as good as a vacation never met any of the Witches of Karres-nor experienced their amazing talent for getting Captain Pausert into trouble.