treachery; treacherous designs
家臣の異心を察した藩主が先手を打った。
The lord, sensing his vassal's treachery, struck first.
異心を抱く者が密かに動き出していた。
Those harboring treacherous intent had begun to move secretly.
忠誠を誓いつつも異心を秘めていた。
He kept his treachery hidden while pledging loyalty.