After the shipwreck, Alonso, Sebastian, Gonzalo and Antonio search for Ferdinand since he was separated from the rest of the mariners. As they go on their search, Gonzalo comments that it isn't so bad being stuck on the island and Alonso spills out his feelings of regret of marrying away Gonzalo's daughter.
Sebastian tells Alonso that it's his fault that they're now stranded on the island and that everything is going wrong for them. Once Ariel comes and plays his music, all but Sebastian and Antonio are asleep. In this time, Antonio convinces Sebastian that he should kill his brother so he can easily take over the position on the throne.
"We heard something!"
After Antonio was able to convince Sebastian to kill his brother, they both take out their swords to prepare to kill him.
Is there more value in vengeance or virtue?
Ariel comes back and whispers in Gonzalo's ear as he sleeps to wake him up before Sebastian or Antonio could do anything to his brother.
"Preserve the King!"
Sebastian is able to quickly lie and say that they heard a loud noise in the distance, causing them to draw their swords. Gonzalo is suspicious but lets it go.
There is more value in virtue because showing or giving good morals will get you the exact same in return rather than the other way around to simply get hurt again.