Note: There are no breaks in the Crito as Plato wrote it. These notes on the text were made later, sections beginning or breaking off where a new theme or topic is introduced or dropped. Sections in this guide are demarcated according to the Stephanus numbers (the page numbers from the 1578 complete works edited by Henri Estienne ("Stephanus" in Latin)). For Plato, the Stephanus numbers are the standard page references, and most editions of Plato's work contain the Stephanus numbers along the margins.
The dialogue opens just before dawn as Socrates awakes in his prison cell to find his old friend Crito watching over him. Crito explains that he has been watching over Socrates for quite some time, but dared not wake him. Worried about his friend's impending death, Crito was unable to sleep and decided to visit. He expresses admiration at Socrates' composure and calm sleep under such adverse conditions. Socrates replies that it would be odd to fear death at his old age.
Crito explains that he has come at this early hour because he fears Socrates' execution is near at hand. The annual sea-mission to Delos, during which time no prisoner can be executed, has arrived at Sunium on the Attic mainland, and should be returning to Athens soon. The sea-mission is in celebration of Theseus' victory over the Minotaur and the Minoan civilization that once dominated the Mediterranean world from its homeland in Crete. The boat left the day before Socrates' trial, and so Socrates has spent a good deal of time in prison already. Crito predicts that the boat will arrive in Athens this very day--meaning that Socrates would be executed tomorrow. He notes that this news will probably not concern Socrates greatly, but that he, Crito, and Socrates' other friends are taking the news very hard.
Socrates replies that he doubts that the expedition will arrive today. Last night while he slept, he dreamt he saw a beautiful woman in white robes who, quoting the Iliad, said "To the pleasant land of Phthia on the third day thou shalt come" (44b). While Crito expresses puzzlement at this dream, the meaning, to Socrates, is quite clear: he will not die for another three days. Because he is to be executed the day after the expedition returns, the boat cannot possibly return until at least tomorrow.
Unlike many of Plato's dialogues, there is no framing device in the Crito: we are launched immediately into the dialogue, with Socrates' first words upon waking. This strategy is more characteristic of Plato's earlier dialogues, where a more historical representation of Socrates is given. In the middle and later dialogues, in which the character of Socrates becomes increasingly a mouthpiece for Plato's own views, elaborate framing devices are set up so that Socrates' own words are recounted by a friend of a friend who heard about it from another friend--or some such thing. Here, we get Socrates' own words more directly, though we should note that Plato himself is nowhere present; the account is at best second-hand.
In spite of this formal hint that the Crito is an earlier dialogue, there is a great deal of debate regarding its date of composition. Stylistically, it varies quite a bit, and many of the characteristic elements of an early dialogue are missing. There is no claim on Crito's part to be an expert in any field, nor does Socrates show Crito to be ignorant. Not only does the dialogue lack the cross-examination and irony of a typical early Socratic dialogue but, as we shall see, it contains positive doctrines more characteristic of Plato's more mature works.