2 sentences

1. 他们正在暗中图谋不轨。

   tā​men zhèng​zài àn​zhōng tú​móu bù​guǐ.

   They are secretly plotting something bad.

   Source: Dong Chinese Dictionary

2. 他因图谋不轨而被警方逮捕。

   tā yīn tú​móu bù​guǐ ér bèi jǐng​fāng dài​bǔ.

   He was arrested by the police for plotting illegal activities.

   Source: Dong Chinese Dictionary