Read The Witches of Karres Storyline:
Captain Pausert, master of the old pirate-chaser Venture , seems to have a knack for selling job-lot cargoes around the fringes of the Empire. He’s so ahead of the game that he has time to rescue three child slaves, only to find out that they are three witches of Karres with awesome psi powers.Nominated for Hugo Award for Best Novel in 1967.
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