Note: There are other series with the same name:

Doors (神坂一 series)^?ドアーズ
Doāzu
Doaazu

• Series: Doors Series Record # 52044
• Note: A German series by Markus Heitz with different concept than most series: instead of having consecutive publications, which build up on each other, the novels can be read in arbitrary order. Deduced from a rough comparison at Amazon's Look Inside it looks like the first three novels of the first "season" of the series all start with the same, or at least a very similar, text. When the end if this part is reached, the characters have to choose one of several doors to go though, and the reader can make the same choice by choosing one of the novels of a series' "season". Each novel represents one of the doors. The beginning part was also published separately as a so-called "Pilotfolge" (engl. "pilot"), similar to a television pilot of a television series.

• Doors
  • 0 Der Beginn (2018) [SF] by Markus Heitz
  • Kolonie (2018) by Markus Heitz
  • Blutfeld (2018) by Markus Heitz
  • Dämmerung (2018) by Markus Heitz