замыслить ( вн. , + инф. )
plan ( d. , + to inf. ); scheme ( d. , + to inf. ); conceive ( d. ); ( намереваться ) intend ( d. , + to inf. ), contemplate ( d. , + to inf. )
что вы замышляете? — what are you up to?, what are you planning? what's your game? разг.