Three parts — from the pre-dawn cell to Socrates's final word.
Crito moves in a single unbroken arc across one morning. Part one establishes the situation — the ship is due, escape is possible, Crito has everything arranged. Part two is the long argument: Socrates dismantles Crito's reasons one by one, returns to first principles, and reaches the question that matters. Part three lets the Laws speak for themselves. From that point, Crito has nothing more to say.
The dawn visit — Crito arrives with news and a plan.
Before dawn, Crito sits in silence beside the sleeping philosopher. He has bribed the guard and come with a plan and money. Socrates wakes, recounts a dream about Homer's Phthia, and calmly estimates the ship is still two days away. Crito insists it may be sooner.
The argument — Socrates refuses, step by step.
Crito makes three arguments: the friends' reputation will suffer; the children will be abandoned; escape is easy and cheap. Socrates returns to first principles — the opinion of the one who knows, the supremacy of the soul, the impossibility of answering injustice with injustice — and shows that the only remaining question is whether escape itself is unjust.
The Laws speak — and Crito falls silent.
Socrates personifies the Laws of Athens and lets them speak directly: they raised him, educated him, and allowed him to stay or leave freely for seventy years. His residency was consent. Escape would make him an enemy of every well-governed city. Crito says nothing. Socrates ends with his final line.