Dharmatatva
Published as vol. I in 1888 (in book form), is a companion of the Krishnachaitra. and because of that, it is believed that Bankim, probably, planned to write a second volume on the present subject. It is not quite clear if some of the essays and his unfinished works explaining the meaning and significance of verses from Gita, published as a collection named Srimadvagabat Gita, would form part of that volume.
Acknowledgement:
Much of the materials for this article was sourced from the Bankim Rachanabali (Complete Works of Bankim Chandra), Tuli-Kalam, Calcutta 1986