Mcbeth ends Act 3 by deciding that he will go back to try to find the weird sisters again and learn more from them.What prompts him to do this?What is the significance of him searching out the wierd sisters rather than bhaving them come to him as in Act 1

Macbeth is reaching the height of his paranoia at this point in the play. He knows Macduff did not come to his dinner. He also knows that Fleance has escaped murder. Macbeth is all about safeguarding his throne. He has become reliant on the witch's information. The Witches of course are merely manipulating him but Macbeth's increased reliance on them shows just how far he has courted the forces of darkness. Really there is no turning back for Macbeth anymore.