The “Apology” (of Socrates) is the most famous dialogue written by Plato. It is one of the main historical sources of Socrates’ life and thought because, as is well known, Socrates has never written anything.
The dialogue tells the story of the trial to Socrates and his condemnation to death. Socrates was accused of moral corruption of young people and of leading them to atheism. His philosophy was incompatible with Greek polytheism and anthropomorphism. Socrates does not fear death because to die as such is neither morally good nor morally evil. He only cares about doing what is just, even if that means accepting a death sentence.
Plato’s Apology is a must for whoever cares about ethics and the roots of Western civilization.
It is also freely available online, for example, HERE!