Macbeth's duplicity

Macbeth is very two-faced once he has killed the king. He is able to maintain some composure when the nobles discover the king's death; however, we have previously seen him falling apart as he brings the knife from the chambers and freaks out over the blood all over his hand. He is kind to Banquo one minute and then arranging his murder the next. He definitely is two faced. He even plots with his wife initially and then shuts her out once he becomes king.