The Enterprise pursues a vessel and rescues its occupants, interstellar con man Harry Mudd, who is arrested on outstanding charges, and three incredibly beautiful women, his cargo. After Kirk diverts to a mining planet to obtain new dilithium crystals for the Enterprise, Mudd negotiates with the three miners there, exchanging his women for dilithium crystals for his own profit. Finally, Mudd’s deception is revealed as the women are, in fact, very plain and only appear beautiful due to taking illegal Venus drugs. Kirk obtains the crystals he needs and takes Mudd back into custody