Who are Lem's envoys of humankind and why do they fail so dramatically to break out of their routine patterns of thinking? The answer may lie in a number of striking imbalances which TheInvincible displays in the presentation of its characters.

Only Horpach, the Commander, and Rohan, Navigator and second-in-command, are given enough prominence to emerge as individuals. Even at that, the differences between them are carefully balanced so that their individuality is only as separate as two sides of the same coin.

Rohan's character, as he grudging identifies with Horpach, merges with his image of his superior to the point that he dreams of himself becoming "commander of the Invincible some day."

Aloof and reserved towards the crew, both leaders regard each other in no less rigid and hierarchical terms. In their relationship they have never risen above a strictly professional level; in fact, although "they had...