Het Geheim van de 7 Bollen
Casterman · 1989–1991 · 5 issues
About the series
A five-issue Franco-Belgian mystery serial published by Casterman from 1989 to 1991, Het Geheim van de 7 Bollen (The Secret of the 7 Balls) unfolds a self-contained puzzle-box narrative. Though details remain sparse, the series is remembered as a compact, atmospheric thriller from the late-album era of European comics.