Dhritashtra summoned Yudhishthira and asked him whether the Pandava wished to inherit the kingdom. Yudhishthira replied that while he would not refuse to rule the kingdom, the decision was Dhritashtra's to make.
Dhritarashtra then told Yudhishthira that he was going to send both the Pandavas and Duryodhana away for a while. Yudhishthira accepted the order and started to make preparations for Kunti and his brothers to leave for Varanavata.
His plan to get the Pandavas out of the capital having succeeded, Duryodhana and his brother Duhsasana plotted to make sure that they would never come back. They dispatched Purochana, their minister, to Varanavata to build a flammable house for the Pandavas and to burn the house down at the earliest possible opportunity.
But Vidura was wise to the plots of Duryodhana. He warned Yudhishthira on the way to Varanavata in a very round-about way to be wary. Yudhishthira understood Vidura's message - that the house was flammable, that they should escape in a tunnel and wander around in disguise.
The Pandavas acted non-chalant as Purochana led them into the fire trap. Vidura sent the Pandavas a miner who approached Yudhishthira when Kunti had asked Purochana to accompany her to the Siva festival. Yudhishthira told the miner to start to dig a tunnel starting at the river bank and ending inside the house.
The day that the miner finished digging the tunnel, just fourteen days after he started, there was a heavy wind and conditions were ripe for a fire. Kunti and four of the Pandavas entered the tunnel. Bhima remained to accost Purochana. The Pandavas placed six corpses that the twins had found in the cemetry on their beds.
Bhima asked Purochana whether he wanted to stay in the house. Purochana said he was guarding the entrance to make sure that no one entered (and, Bhima thought to himself, to make sure that no one left).
"Are you sure that you wish to stay even if the house burns down tonight?", asked Bhima. But Purochana, scared of Duryodhana, said he wished to stay in the house. So, Bhima set fire to the house and escaped through the tunnel. Purochana died in the flaming house.
The house burned through the night. The next morning, the miner closed the tunnel entrance both from below, and when in a crowd looking through the remains, from above. Thus, every one assumed the corpses were those of the Pandavas and of Kunti.
When Dhritarashtra heard that the Pandavas' burned bodies had been found, he knew that it was his sons who had killed them. He summoned Duryodhana and asked if the fire was an accident.
"Purochana was your minister," said the blind king, "and Pandu is now truly dead."
Duryodhana affirmed that the fire was no accident, but the king could nothing to harm his murderer of a son, because after all if not Duryodhana, there was no one else.
The Pandavas found, on the river, a boat sent by Vidura and escaped in it to a forest where they donned the disguise of wandering Brahmanas. It was while they were thus wandering the forest that they entered a village where a demon, Vaka, was terrorizing the village. Bhima killed Vaka, enjoying a huge meal in the process . Although no one else knew that it was Bhima, Vyasa knew and it was thus, that they came to learn the story of Drupada's plans for revenge on Drona.