Q, played by John de Lancie, is a fictional character in the Star Trek universe who appears in Star Trek: The Next Generation, Star Trek: Deep Space Nine and Star Trek: Voyager. The name "Q" is also shared by other members of the Q Continuum. Gene Roddenberry chose the letter "Q" for the character and race in honor of his friend, Janet Quarton.citation needed]
Q is a mischievous, seemingly omnipotent being who has taken an interest in humans. Q's power is limited only in that he cannot overcome others in the Q Continuum, and, like others of his "species," he has not demonstrated the ability to read the minds of sentient beings. However, they can kill each other (as can non Q continuum members) if they have the right weapons. He also has a flair for the dramatic, with a mercurial personality that switches between a joking, camp style and a more ominous and even dangerous manner. While he is boastful, condescending and threatening, he arguably has humanity's best interests at heart, as seen in the series finale, All Good Things..., in which he causes Jean-Luc Picard to shift through time periods, giving him a chance to save humanity. In his portrayal of Q, John de Lancie used as his inspiration a description attributed to Lord Byron: "Mad, bad and dangerous to know."
Beginning with the pilot episode of Star Trek: The Next Generation, Q became a popular recurring character, in large part because of the comedic and dramatic chemistry between de Lancie and Patrick Stewart (who played Captain Jean-Luc Picard). Interestingly enough, de Lancie always felt that each portrayal of Q was the last time he'd take up the role.citation needed]