The plot of Grendel is based on that of the Old English poem Beowulf, though not in an especially straightforward way. The main action of Beowulf breaks into four parts: the Grendel episode …; the subsequent battle with Grendel's mother …; the return voyage …; and the dragon fight…. In the original, each major conflict concludes before the next begins, and a fifty-year successful reign by Beowulf separates his fight with the dragon from his conquest of Grendel and his mother. Gardner's novel opens with Grendel ravaging Hrothgar's meadhall and men, and ends immediately after the fight with Beowulf, Grendel's death being imminent: this episode represents only about one-fourth of the Anglo-Saxon poem. Both Grendel's mother and the dragon appear, but Gardner assigns them new functions, as well as departing from the chronology of the original.

Gardner's restructuring of the Anglo-Saxon original, which strikingly alters the epic material, points to further...