A first-person narrator is a principal persona in a Grass fiction, but in no major work before The Rat has the authorial Grass been so fully explicit.

Grass tells us quite directly how he is constructing his story. This omniscient, persistently self-intrusive character is joined by a second one, nearly as richly developed — the She-Rat — whom Grass has wished for and received for Christmas. The two thereafter join in a novel-long dialogue. The She-Rat's function is to tell the story of the nuclear holocaust and its aftermath, which may or may not have already occurred. But it is clear that it will.

Another important character is Oskar Matzerath, now almost sixty years old, the jaded and self-absorbed protagonist of The Tin Drum (1959) who, in Grass's first and greatest novel possessed a charismatically weird elementalness that is now lost. Another major character is Oskar's 106-year-old grandmother, Anna...