Brutus has insomnia (II.i.4, 62). He delivers a nighttime soliloquy in his orchard concerning his fears of Caesar's ambition and his foreseeing tyranny after the coronation, unless he join in the assassination plot. It's "no personal cause" (II.i.11) and rather abstract for a motive, but "Brutus is one more study of a man who undertakes a role for which nature never intended him" (Goddard, I 308). Brutus likens Caesar to a serpent's egg: we'll "kill him in the shell" (II.i.34), or abort a tyrant fetus. The instruction "Fashion it thus" (II.i.30) "is to acknowledge that there is no plausible complaint to make against Caesar: 'Fashion it thus' means to make up your own anxious fiction, and then believe in its plausibility" (Bloom 108).
Brutus' young boy servant Lucius (the name is etymologically connected with "light") brings in a letter that was thrown in the window and that cryptically calls for action and demands of Brutus, "see thyself" (II.i.46). Brutus ruminates a while on this. "Once again, psychomachia, the struggle for control of a soul, is figured here in an image of civil war" (Garber 411). As instructed, Lucius consults the calendar and reports, "March is wasted fifteen days" (II.i.59) -- which implies that it is the 16th, a notion troubling enough for some editors to change the line with no textual authority but that some lines earlier, Brutus had declared tomorrow the ides of March (II.i.40). Is Shakespeare intentionally blurring the matter (or did "ides" really refer to the central days of the month rather than one specific calendar day)? Brutus then hears a "Knock within" -- an interesting stage direction seen also at a key moment in Macbeth.
Cassius and the cloaked conspirators gather. Brutus insists he hasn't slept in a month and, while Cassius and Brutus talk quietly apart, a few of the conspirators quibble about which way is east and where the sun will come up (II.i.101ff). So these Romans who would usher in a new day for the Republic can't even figure out basic geography. "They promise a new spiritual morning before they have even learned where the material sun comes up!" (Goddard, I 317). Casca's pointed sword almost visually indicates that the sun rises at their command. Dopes.
Cassius proposes they all swear an oath (II.i.113). Brutus insists there is no cause for it since they are acting honorably and do not need the additional motivation. The two disagree on the issue of including Cicero in the conspiracy, and on killing Mark Antony along with Caesar. Brutus thinks, "Our course will seem too bloody" (II.i.162); they should think of themselves as sacrificers, not behave like butchers (II.i.166); but "God meat or dog meat, we might retort, the effect on Caesar will be just the same" (Wells 195). "The lofty character of the end intended, the preservation of the liberties of Rome, blinds Brutus to the low character of the means proposed" (Goddard, I 312). Brutus also may get off on taking authoritative charge here; as foremost in moral prestige, he may not want to share the limelight with an equal like Cicero. Some more strained and self-contradictory rationalizing about their plot follows, amounting to this syllogism: "(1) The spirit of men contains no blood. (2) We wish to destroy the spirit of Caesar. Therefore (3) we must spill Caesar's blood" (Goddard, I 318). "Brutus is trying to divide the indivisible, to make murder into something holy. Ceremony in this case is a way of avoiding reality, of sanctifying disorder" (Garber 418).
A clock chimes (II.i.192) -- "one of the more amusing anachronisms in Shakespeare" (Asimov 280) -- or perhaps "The presence of a modern clock in Caesar's Rome abruptly reminds the audience of the double time period in which the play is set" (Garber 411). After some details about getting Caesar to the Capitol, the conspirators depart.
Lucius is asleep and Brutus' wife Portia enters, despite what he calls her "weak condition" (II.i.236), wanting to know what has been bothering him lately. She is the daughter of Cato and therefore supposedly of a superior intellect over ordinary women -- and she has masochistically given herself a "voluntary wound" in the thigh (II.i.300); she wants to share his troubles -- in other words, here's yet another questioning of one's proper "place." "If the matter of Portia's wound were true, then the fact that Brutus was unaware of a bad wound in his wife's thigh until she showed it to him gives us a surprising view of the nature of their marriage" (Asimov 282). Brutus is impressed and promises to tell her his thoughts of late. "Caesar because of his vanity and ambition, Brutus because of a strain of cold rationalism that runs through his nature, are in particular need of the insight of their wives" (Goddard, I 313). Nevertheless, Brutus dismisses Portia with just the promise that he'll explain at a later time.
Lucius wakes up and introduces Caius Ligarius who was sick but has new hope and will follow Brutus in whatever plans. So Brutus has quickly dismissed his wise wife and innocent boy in order to embrace a representative of sickness (Goddard, I 319-320).
On a stormy night chez Caesar, Caesar notes that Calpurnia recently
dreamed of his murder. He has a servant instruct augurers to make a
sacrifice. Calpurnia herself speaks of omens, including graves "yawn'd
and yielded up their dead" (II.ii.18) and even "Horses did neigh and
dying men did groan" (II.ii.23)! She hopes Caesar will not leave the
house. He argues that these are general omens not singling him out, that
the will of the gods is unavoidable, and that since death comes to
everyone one cannot fear it: "Cowards die many times before their deaths,
/ The valiant never taste of death but once" (II.ii.32-33). The servant
reports that the priest could not find a heart inside the sacrificial
animal (II.ii.40), so Caesar should stay home. Caesar has an alternate
reading of the circulatorily-impaired chicken but finally decides to stay
home and to send word to the Senate that he is ill. Note that Caesar speaks
of himself in the third person, which many in Shakespeare's audience may not
have noticed since supreme heads of state would speak so at the time.
In any case, "the pattern of omen and portent in this play is closely
allied to a pattern of misconstruction or misreading, a misreading not
only of signs in the sky, but also of the basic nature of human beings
and their propensity for chaos and disorder" (Garber 416).
Decius enters and will convey the message to the Senate. Caesar explains about Calpurnia's dream of men washing their hands in his blood flowing from his statue. Decius reinterprets the dream in a way that glorifies Caesar and appeals to his vanity. He says the Senate will ridicule his fear of his wife's dreams. Thus Caesar is persuaded to go to the Capitol.
All conspirators except Cassius arrive, as does Mark Antony. Caesar invites them to drink wine (and it's around 8:00 in the morning! what a guy!) and then, "like friends" (II.ii.127), to proceed to the Senate together.
Artemidorus reads a letter he has written to Caesar, naming the conspirators to beware of. He hopes to give Caesar the letter as he passes by. Artemidorus is remarkably up-to-date, since Brutus and Ligarius joined the conspiracy only a few hours ago.
Portia gives Lucius choppy commands regarding an errand to the Senate. She indicates that Brutus has revealed his plan and is jumpy and nervous about noises. A soothsayer is on his way to the Capitol. Portia asks him about plans to harm Caesar. He knows nothing about that but does fear for Caesar. Lucius heads off with a greeting to Brutus from Portia; whether or not he is irked by personal calls at the office, Brutus is to report back again to her.