In the earlier episode of The Story of Mahabharata, we learnt that the Pandavas lost the gamble and had to leave at once for the wilds for a period of thirteen years. Kunti, the mother, was too weak to face the hardships of the exile, therefore, she stayed back. The brothers, along with their wife, Draupadi, set out for the wilds.
The next thirteen years are all about Pandavas’ struggle in the wild. Remember, they were the sons of different gods, so there was some divine connection. They kept praying to their gods and strengthened themselves in this arduous journey. There are numerous temples, spread across India, which are believed to have been the stay of the Pandavas during their exile.
Coming back to the story, there is an interesting event that takes place in the forest. One day, the four Pandavas (except Yudhishthira, the eldest brother) got consumed by a magical creature called Yaksha. When Yudhishthira encountered Yaksha, the latter asked him a number of philosophical questions, all of which were answered correctly by Yudhishthira. Satisfied by his responses, Yaksha returned the brothers as well. Here are some of the questions and their respective responses by Yudhishthira.

Question: What moves swifter than wind? Answer: Mind. Question: By losing it, you become rich. What is it? Answer: Greed. Question: What is man's biggest enemy? Answer: Anger. Question: What is the greatest wonder? Answer: A man sees people dying every day, but he refuses to believe that he would also suffer the same fate one day.
So that’s how the exile goes. There is magic and adventure and numerous stories of the wild. As mentioned before, the thirteenth year of the exile was going to be a secret one. If anyone saw the Pandavas during that year, the exile would begin all over again, for another thirteen years. Which is why, Pandavas decided to disguise themselves as different people as they entered a distant kingdom. Yudhishthira would work as a Brahmin advisor at the king’s court, Bheema would work as a royal cook and Arjuna (who was cursed to be a eunuch for a year) would do singing and dancing. Similarly Nakul and Sehdev also worked there, along with Draupadi who was queen’s personal maid.
This was the time when Duryodhana was desperately looking for the Pandavas. He wanted to locate them so he could extend the exile for another thirteen years. For that reason he sent out his spies in all directions. Eventually they got some clues. At this point Duryodhana decided to attack that kingdom.
As the battle was going on, at one point, Duryodhana spotted the Pandava brothers fighting in it. “Aha!” he says. “I have seen them. Now they must go back to the exile.”
He was jumping with excitement, until, he was told that the exile period had just ended. So the Pandavas were going to come back. And so was The War of Mahabharata.
