火薬 かやく陰謀 いんぼう事件 じけんでしょう
kayakuimbōjikendeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 火薬陰謀事件

1. Probably the Gunpowder Plot.

Polite
Presumptive
Conjecture