鐵面無(wú)情

- be just and stern (to sb.); a stern look with severe lines about his mouth, without compunction or mercy; disinterested; grave as a judge; impersonal; impartial and incorruptible; not be moved by entreaty, prayer or tears from friends or relatives; not to spare anyone's sensibilities; relentless in his singleness of purpose in the execution of his duties; unmoved by personal appeals