Act 2, Scene 1
Banquo, who has come to Inverness with Duncan, wrestles with the witches' prophecy. He must restrain himself the “cursed thoughts” that tempt him in his dreams (II i 8). When Banquo raises the topic of the prophecy as Macbeth enters the scene, Macbeth pretends that he has given little thought to the witches' prophesy. After Banquo and his son Fleance leave the scene, Macbeth imagines that he sees a bloody dagger pointing toward Duncan's chamber. Frightened by the apparition of a "dagger of the mind," he prays that the earth will "hear not [his] steps" as he completes his bloody plan (38, 57). The bell rings—a signal from Lady Macbeth—and he sets off toward Duncan's room.
Act 2, Scene 2
Lady Macbeth waits fitfully for Macbeth to return from killing Duncan. Upon hearing a noise within, she worries that the bodyguards have awakened before Macbeth has had a chance to plant the evidence on them.
Macbeth enters, still carrying the bloody daggers with which he killed Duncan. He is deeply shaken: as he entered Duncan's chamber, he heard the bodyguards praying and could not say "Amen" when they finished their prayers. Lady Macbeth’s counsels to think "after these ways” as “it will make [them] mad" (32). Nonetheless, Macbeth also tells her that he also thought he heard a voice saying, "’sleep no more, / Macbeth does murder sleep. . . Glamis hath murdered sleep, and therefore Cawdor / Shall sleep no more, Macbeth shall sleep no more" (33-41). Lady Macbeth again warns him not to think of such "brain-sickly of things" and tells him to wash the blood from his hands (44). Seeing the daggers he carries, she chastises him for bringing them in and tells him to plant them on the bodyguards according to the plan. When Macbeth, still horrified by the crime he has just committed, refuses to reenter Duncan’s chamber, Lady Macbeth herself brings the daggers back in.
While she is gone, Macbeth hears a knocking and imagines that he sees hands plucking at his eyes. He is guilt-stricken and mourns: “Will all great Neptune’s ocean wash this blood / clean from my hand?” (58-59)? When Lady Macbeth hears his words upon reentering, she states that her hands are of the same color but her heart remains shamelessly unstained. “A little water,” she continues, “will clear [them] of th[e] deed” (65). As the knocking persists, the two retire to put on their nightgowns so as not to arouse suspicion when others arrive.
Act 2, Scene 3
In a scene of comic relief, the Porter hears knocking at the gate and imagines that he is the porter at the door to Hell. He imagines admitting a farmer who has committed suicide after a bad harvest, an "equivocator" who has committed a sin by swearing to half-truths, and an English tailor who stole cloth to make fashionable clothes and visited brothels. Since it is "too cold for hell" at the gate, he opens the door instead of continuing with a longer catalogue of sinners (16). Outside stand Macduff and Lennox, who scold him for taking so long to respond to their knowcking. The Porter claims that he was tired after drinking until late and delivers a short sermon on the ills of drink.
Macbeth enters and Macduff asks him whether the king is awake yet. On hearing that the king is still asleep, Macduff leaves to wake him. While he is gone, Lennox tells Macbeth that the weather by night was full of strange events: chimneys were blown down, birds screeched all night, the earth shook, and ghostly voices were heard prophesying ominously. A stunned Macduff returns with the news that the king is dead. He tells them to go see for themselves and calls to the servants to ring the alarm bell.
Lady Macbeth and Banquo enter and Macduff informs them of the king's death. Macbeth and Lennox return and Macbeth laments the king's death, proclaiming that he wishes he were dead instead of the king. When Malcolm and Donalbain arrive, Lennox blames the regicide on the guards by pointing to the incriminating bloody evidence. Macbeth states that he has already killed the bodyguards in a grief-stricken rage. At this point, Lady Macbeth feigns shock and faints. Aside, Malcolm and Donalbain confer and decide that their lives may be at risk and that they should flee Scotland. As Lady Macbeth is being helped off-stage, Banquo counsels the others to convene and discuss the murder at hand. Left behind on stage, Malcolm decides that he will flee to England while Donalbain will go to Ireland.
Act 2, Scene 4
Ross and an old man discuss the unnatural events that have taken place recently: days are as dark as nights, owls hunt falcons, and Duncan's horses have gone mad and eaten each other. When Macduff enters, Ross asks whether the culprit has been discovered. Macduff tells him that the bodyguards killed the king. The hasty flight on the part of Malcolm and Donalbain, however, has also cast suspicion on the two sons as well. Ross comments that Macbeth will surely be named the next king, to which Macduff responds that he has already been named and has gone to Scone to be crowned. Ross leaves for Scone to see the coronation while Macduff heads home to Fife.
Macbeth's famous soliloquy at the beginning of this act introduces an important theme: visions and hallucinations caused by guilt. The "dagger of the mind" that Macbeth sees is not "ghostly" or supernatural so much as a manifestation of the inner struggle that Macbeth feels as he contemplates the regicide. It "marshal[s] [him] the way [he] was going," leading him toward the bloody deed he has resolved to commit, haunting and perhaps also taunting him (II i 42). The same can be said for the ghostly voice that Macbeth hears after he kills Duncan, as well as the ghost of Banquo that appears in Act 3. Indeed, almost all the supernatural elements in this play could be—and often are—read as psychological rather than ghostly occurrences.
(But if this is the case, one also wonders about the witches: are they, too, products of Macbeth's fevered mind? The fact that merely give voice to the Macbeth’s dormant ambitions would seem to confirm this idea, but this is countered by the fact that Banquo also sees the same witches and hears them speak.)
The "dagger of the mind" is only one of many psychological manifestations in the play. As the bodyguards mutter “God bless us” in their drunken stupor, Macbeth finds that he is unable to utter the prayer word “Amen.” A psychological literary analyst may perceive this as a physical inability to speak, caused by Macbeth's paralyzing doubt about the correctness of the murder. The inner world of the psyche thus imposes itself on the physical world. The same can be said for the voice that Macbeth hears crying "Macbeth shall sleep no more" (II ii 41). An overwhelming sense of guilt will prevent “innocent sleep” from giving Macbeth respite from his tormented conscience. While he has consigned Duncan to eternal rest, he himself lives now in eternal anxiety.
In addition to his troubled existence, Macbeth's perturbed sleep can also be read as a metaphor for the troubled state of the country. In Macbeth—as with many other Shakespearean plays—there is a close and mirrored relationship between king and the country. In scene 4, for example, Ross reports that "by the clock ‘tis day, / And yet dark night strangles the traveling lamp" (II iv 6-7). This image of the darkness strangling the light of day is a meteorological manifestation of the murder of Duncan; the light of nature is suffocated just as Duncan's life is extinguished. Victorian writer John Ruskin called such mirroring of a character's psychological state in inanimate natural objects "pathetic fallacy." In animate natural objects too, a similar mirroring occurs. The old man describes Duncan's noble horses eating each other and an owl eating a falcon--events that echo the slaughter of Duncan by Macbeth. Thus the unnatural death of Duncan plunges the country into both physical and spiritual turmoil.
The image of an owl hunting a falcon is part of a greater framework of symbolism surrounding birds in the play. When Duncan approaches Inverness in Act 1, for example, he comments on the martlets that he sees nesting on the castle walls. He takes this as a good sign—martlets are lucky birds. Lady Macbeth, on the other hand, mentions earlier in this scene that there are ravens croaking on the battlements. She takes this as a harbinger of Duncan's death. Duncan, the trusting optimist, sees lucky birds, whereas Lady Macbeth sees ominous ones. One sign does not exclude the other: for Duncan, "fair" becomes "foul" as the lucky martlets metamorphose into the deadly ravens.
In Act 2, characters discuss or see birds in almost every scene. While Lady Macbeth is waiting for Macbeth to finish killing Duncan, for example, she hears an owl hooting and calls the owl a "fatal bellman"—a bird whose call is like a bell tolling for Duncan's death (II ii 3). The owl could also be "fatal" as an instrument of Fate, just as Macbeth is in some ways an instrument of Fate through the intervention of the Weird Sisters (keeping in mind that "wyrd" derives from the Old English word for "fate"). In this respect, one observes a mirroring between Macbeth and the owl: both hunt at night; the owl is observed killing a falcon, just as Macbeth kills Duncan.
Over the course of Macbeth, dreams, symbols, fantasy, and visions impinge upon the "real world." The witches' fantastic prophecy is realized. The "dagger of the mind" points the way to a murder committed with a real dagger. And in the Porter scene, the Porter imagining that he guards the gate to Hell ironically creates a gate of “real” hell caused by regicide. When the Porter opens the gate for the thanes, he mentions that he and his friends were out "carousing till the second cock" (II iii 23). This statement calls to mind the cock that crows in the New Testament after Peter betrays Jesus by denying knowledge of him (Matthews 26; Luke 22). In Macbeth, the betrayal occurs in a more active form as Macbeth murders Duncan after the crows of the cock.