Leopold Fieseler, a detective with the Zeon Public Peace Department/Zeon Public Safety Department is charged with investigating terrorist attacks against Zeon government officials led by an anti-Zabi group called Valkyrie. While researching to find out who were the culprits, Leopold gets into trouble when Valkryie supporters within the ZPPD/ZPSD "arrest" him for getting his hands into classified information to help find out who are the culprits for a planned terrorist attack against Gihren Zabi himself.

The manga draws parallels with the 20 July 1944 plot.