 Every "Valérian" adventure from "Bad Dreams" to "The Rage of Hypsis" was first serialised in the Franco-Belgian comics magazine "Pilote".The first story to be collected in comic album format was "The City of Shifting Waters" which was numbered "1" in the series.When "Bad Dreams" was eventually collected as an album, it was given the number "0" to reflect its position as the debut adventure in the series.