Bachitra Natak, the wondrous drama, is a composition in the Dasam Granth containing what is effectively an autobiographical account: the Guru's lineage, his sense of his own purpose, and narratives of the battles of Bhangani and Nadaun.
It is one of very few first-person accounts by any figure of that period in India and the only one by a religious leader who was also a commander.
Its account of Bhangani in 1688 names the Pathan mercenaries who left, the Udasi sadhus who stayed, and Pir Buddhu Shah who came with his sons.
It states the purpose plainly: that he was sent to uphold righteousness and to destroy the wicked, and that he does not regard himself as anything other than a servant.
For historians it is the closest thing to a primary source for the Anandpur period, and its authorship, like the rest of the Dasam Granth, is argued.
It gives an account of the descent of the family, of a previous life at Hemkunt, of the reason for being sent, and of the actions fought at Bhangani and Nadaun.
It is written in Braj in a strongly rhythmic metre and it breaks off unfinished, which is one of the standing questions about its transmission.
It is the closest thing to an autobiographical statement in the whole Sikh corpus, and the argument over the authorship of the Dasam Granth applies to it as to the rest.