20th Century Boys follows a group of childhood friends who, as adults at the close of the 20th century, discover that a symbol and a fictional "Book of Prophecy" they invented as children have been repurposed by a mysterious cult leader known only as "Friend" into a real plan for global catastrophe.
This fourth volume — Band 4 in Panini's German edition, matching volume 4 of the original Japanese and VIZ English releases — continues the group's fight against Friend's organization. Kenji, now a fugitive, goes into hiding to plot how to strike back, while the story shifts focus to Otcho, a member of the original group who resurfaces after a long absence abroad and is drawn back into the group's orbit. Elsewhere, a man called Shogun is pursued through the criminal underworld of Bangkok as the search for a way to stop Friend intensifies ahead of the approaching millennium.
This is the standard numbered Panini/Planet Manga German edition (not the later "Ultimative Edition" re-release, which uses different volume numbering and ISBNs).