First published in 1965 this book is the continuation of Bion's investigation of various aspects of psychoanalytic theory and practice. He examines the way in which an analyst's description of the analytic experience necessarily transforms it, in order to effect an interpretation.
The edition I read wasn't this one, but rather the William Heinemann Medical Books Ltd. publication, a white book with red lettering and bordering.
I found this book difficult to understand, and even by Bion standards. He was always trying to give psychoanalytic theory a kind of mathematical precision (i.e., the grid), but here he takes such things much farther, to the point of (for me, at least) impossible obscurity.
When he gets into his discussions of O and "the void and formless infinite," it gets more interesting.