For more than thirty years, Fritz Leiber has been giving his readers glimpses of Heaven and Hel in his own special time machine/spaceship theater. One might describe it, if the metaphor is not too conventional, as the theater of his imagination. Such a metaphor is more accurate than usual in the case of Leiber, since he often designs his stories according to theatrical conceptions. (p. v)

The influence of theater upon his work is more than just a simple costuming of his fantasy and science-fiction stories in the paraphernalia of the stage, more than just the fact that his characters often perform plays or put on little shows or gather together for poetry and song recitals in the course of their adventures. The ideas, structures, and machinery of the drama, as practiced from the time of the ancient Greeks right up to the present, are such basic elements in his fiction that it is difficult to find a Leiber story or novel that does not, in some way, suggest his ties to the theater. (pp. v-vi)

Leiber's work has been distinguished for his ability to create mood, especially the dark mood of the occult and supernatural, and to tell stories complex in plot and theme at a fast pace. He is perhaps better than any other fantasy-sf author at creating good dialogue (although in some science fiction circles, that observation might be classified as faint praise). He has the knack of writing emotionally-charged dialogue that is believable and effective, without resorting to the kinds of melodramatic formulae so common to the genre. And he portrays character vividly, whether the character is human or alien. In a literature often accused of male chauvinist leanings, he has consistently etched effective characterizations of women and, in advance of the current women's lib concerns, shown understanding of and sympathy for the role of women in a male-dominated society. In fact, many of Leiber's themes, derived perhaps from his continuing interest in liberal beliefs and causes, are underlain with politically-radical ideas, especially when viewed in light of the generally reactionary themes of many of his contemporaries in the field. In addition to his work in fantasy and science fiction, he has made his mark in the related sword-and-sorcery subgenre with his memorable tales of Fafhrd and the Gray Mouser.

Looking back on Leiber's work, I came to the conclusion that its best features derived from his concern with, and interest in, theater. Most of these are to be found in the Hugo Award winning novel, The Big Time, as well as in some of the other stories in the Change-War cycle. (pp. vii-viii)

The Change War is one of those intriguing science-fiction concepts that makes other sf writers envious and leaves readers breathless. Still, the depiction of soldiers fighting a war across time, rearranging history as a part of the overall battle, would be just a clever one if Leiber had chosen to treat it in a conventional sf way. Instead, his selection of setting (a rest and recuperation center outside of the war and, for that matter, time) is a shrewd device, particularly in the way he is able to suggest the range and character of the time-war through the statements and thoughts of the people in The Place. Also, his treatment of his major themes (time and change especially) gives the narrative a solid philosophical framework that makes the plight of these minor warriors and entertainers all the more poignant and mysterious, almost in a Shakespearian way…. Much of [The Big Time] is concerned with the ideological frustrations of Greta and the others, trapped not only for a few hours in The Place but for always in a war whose meaning they can only theorize about…. Each of the individual thematic speculations could become the basis of single novels. Leiber, on the other hand, packs them securely and effectively into this relatively short novel.

Leiber's mastery of divergent styles, a praiseworthy characteristic of all his work, is especially evident in The Big Time, with its rich mixture of poetic language and slang. Much of this richness comes from the influence of his dramatic background on the writing. (pp. viii-ix)

Perhaps the finest achievement in this novel is the character of Greta, who starts out appearing to be what she says she is, an ordinary Entertainer plucked out of her ordinary lifeline, but who, by the end of the story, has become a kind of Everywoman who perceives events and people more clearly and more eloquently than any of the other characters…. After choosing Greta as the tale-teller, [Leiber] strived to make it seem as if she were talking to somebody rather than writing the story down. The audience he envisions for her is one or more new recruit-entertainers on the verge of entering the Change World. The fact that Greta is such a fascinating character attests to the success of his method. Again the approach is essentially theatrical, deriving chiefly from the dramatic monologue. (p. x)

The most striking similarity to theater is Leiber's use of dialogue. The men and women who are his players often talk as if on a stage…. Conflicts between characters are structured according to dialogue exchanges which are "built" in intensity, according to theatrical custom. Most important of all, it is well-written dialogue…. (p. xi)

Of all the narratives in the Change-War Cycle, The Big Time is the most daring, the most flamboyant, and the most significant as a contribution to science fiction. In it Leiber shows how a concept that has seemingly been done to death can be resurrected by taking a new slant on the subject. Time travel has been again and again declared a dead science-fiction theme by readers and writers alike, yet Leiber and others keep returning to it and discovering that there are still areas of the subject that have possibilities. (p. xiv)