Mucius Scaevola has always been one of my
heroes, since the early days when I was reading my dad's Latin books. This sort of story is why you should read
Livy. I just want to add a bit to the above.
His first thought, young and foolish as he was, was to sneak out in the night and perform the brave deed off his own bat, but then he thought he could easily be caught and punished as a deserter. Rome was under siege; they had just expelled their kings, the Tarquin dynasty, who had taken refuge with the Etruscans. Lars Porsena or Porsenna was a good man but was morally bound to his kinsfolk the Roman kings, so he had advanced on the new republic to restore the Tarquins.
Rather than be tarred with the reputation of infamy if his adventure failed, Mucius proposed his plan to the Senate. So he infiltrated the Etruscan camp with a dagger concealed in his clothing. The story goes as Compenguin above has written.
When caught he spoke proudly.
I am a Roman, my name is Gaius Mucius. I came here to kill you -- my enemy. I have as much courage to die as to kill. It is our Roman way to do and to suffer bravely. Nor am I alone in my resolve against your life: behind me is a long line of men eager for the same honour. Gird yourself, if you will, for the struggle -- a struggle for your life from hour to hour, with an armed enemy always at your door. That is the war we declare against you: you need fear no action in the field, army against army; it will be fought against you alone, by one of us at a time.
(Translation of
Aubrey de Sélincourt, in Penguin.) Lars Porsena furiously ordered him
burnt alive. At this point Mucius performed his heroic act of treating his body with
scorn, thrusting his hand into the sacrificial flame.
Astonished at this courage, Porsena released him. As if in gratitude for that, Mucius told him the story he had only hinted at before: three hundred young Roman noblemen like himself had sworn to attempt Porsena's life, and Mucius had been drawn first by lot.
Lars Porsena withdrew his besieging forces from Rome, unable to bear the thought of three hundred people equal in endurance to Gaius Marcius Scaevola.