Banquo is starting to wonder if Macbeth is up to no good. He even suspects (quite rightly) that Macbeth is the king’s murderer. After all, he witnessed the witches’ prophecy, so he knows what Macbeth stood to gain. When Macbeth, the newly crowned king, arrives on the scene with all his attendant lords—and his wife—Banquo plays nice and then promptly leaves. Left alone, Macbeth begins to worry out loud about Banquo. Macbeth knows he’s a good guy, but he also knows that Banquo heard the prophecy. He thinks Banquo might figure things out. Plus there’s the fact that the witches foretold that Banquo’s descendants would one day be kings—not Macbeth’s. All this adds up to one thing: Macbeth wants Banquo and his son dead. With Banquo and Fleance both dead, the prophecy for Banquo couldn’t possibly come true. He has his servant bring in two men he had waiting at the gates, convinces these men that Banquo is their enemy, and hires them to do away with his one-time friend.