Five brothers in a forest, a long way into an exile, and no water anywhere.
Sahadeva went to look and found a lake — clear, cold, full. And as he knelt down, a voice said: answer me first, then drink.
He drank. And he fell down beside it.
Nakula went after him and found his brother lying there and the water beside him, and the voice said the same thing, and he drank, and fell.
Arjuna went. Then Bhīma. Each of them saw the ones before, and each of them was told, and each of them drank.
Yudhiṣṭhira came last and found all four of them on the ground.
He was as thirsty as any of them. He did not drink.
He said: ask.
There was a yakṣa there — a crane on the bank, which is what the voice had been — and it asked a great many questions, and he answered every one.
Then it asked the famous one. What is the greatest wonder in the world?
And he said: every day, people watch other people die. And every single one of them goes on believing it will not happen to him. Nothing is stranger than that.
The crane said: you have answered. I will give you one brother back. Choose.
And he said: Nakula. Not Bhīma, who is the strongest. Not Arjuna, who is the reason they have any chance at all.
He explained it in one breath. My father had two wives. I am Kuntī's son and I am standing here — so let a son of Mādrī stand up too. If only one of us lives, it should not be that one whole mother is left with nobody.
The crane was his father, and had been from the first question. All four of them got up.
Four of them saw four brothers lying beside the water and drank it anyway. He was the only one who stopped.