It was Nakula who observed that their kitchen, in the new house smelled of butter, even when, there was no butter in the kitchen.

He told Yudhishtira about this, and on further observation, he found that the house was made up of flammable materials. Yudhistira remembered the parting words that Vidura whispered in his ears.

Realization dwelled on the Pandavas that, they have been enticed to live in a fire trap.

But they decided to feign ignorance. A secret laborer sent by Vidura, dug an escape tunnel for them.