One evening, Cat's Eye is unexpectedly visited by Hans Schmidt, their father's tutor in the arts. Schmidt asks the Kisugi sisters to recover a bottle of wine from 1944, which sports a label bearing one of Heinz's sketches; the bottle in question, believed long lost, is being offered at an auction at the Tokyo Oriental Hotel. Cat's Eye manages to get the bottle, but the wine turns out to be the key to a terrible chemical weapon jointly developed by Nazi Germany and the Japanese Empire - and a band of hardline Nazi veterans intends to make use of it to resurrect the Third Reich.