Sassy Amsterdam schoolboy Franciscus 'Ciske' Vrijmoeth alias 'the rat' has to stay with his mother, a wasteful lush who cares only for her lovers but neglects or even abuses her children, left like the household to her sister Chris. Ciske's dad Cor adores the doting boy, but couldn't stay with adulteress Marie (the other kids are probably illegitimate) and works as sailor, later becomes unemployed. Loveless ma had Ciske committed to an institution and sabotages teacher Bruis's efforts to help the kid after a rebellious incident in his previous school. She only sees him as blackmail or just to hurt Cor, who also gets a new partner, Jans, a fit substitute mother if they can get Ciske after a divorce. But trying to spy on ma for pa, Ciske gets into tragic trouble.
—KGF Vissers