The tragedy of Macbeth by William Shakespeare is basically about a man named Macbeth, who three witches predict will become king. Indeed Macbeth does become king but at the cost of killing to get what he wanted. He killed Duncan, who was the king at the time and he also hired murderers to kill Banquo and Fleance. Banquo and Fleance were two men that Macbeth feared because he believed they were suspicious of him killing Duncan. Though Fleance escaped. Now Macbeth plans to meet to the witches ounce again to see if they have anything more to tell him.
In all of Shakespeare's Five Act tragedies the "turning point" is always somewhere in Act III. The turning point can be defined as the crucial moment when the fate of the hero is sealed, when the events of the turning point have taken past the play must start on its way to a tragic end. To put it in simpler terms it can be defined as the point of no return. Two Acts later is the climax.
In my interpretation the turning point is in Act III Scene v lines 28-33, Hecate the leader of the witches says "As by the strength of their illusion Shall draw him on to his confusion. He shall spurn fate, scorn death, and bear His hopes "bove wisdom, grace, and fear; And you all know security Is mortals" chiefest enemy". I interpret this to mean the witches are going to confuse Macbeth. He will feel so secure, so confident that he will not believe he can face death or lose his throne. This confidence will turn into his enemy, it will be the reason he loses his throne or his life. In my belief this must be the turning point because the three witches predictions have always come to pass, as the reader can see from earlier on in the play. The future is already set for Macbeth once the witches have made their prediction. There is no going back he will face the loss of his life. I believe this because just like in other Shakespeare tragedies death is what comes at the end.