Residual sewer gas from the Watergate explosion has leaked to the surface. John Dean has written a book the aims of which are first to make money and second to disprove Joseph Alsop’s contention that its author is a “bottom-dwelling slug.” The new material in Blind Ambition consists mostly of the part of John Dean’s story he was afraid to tell under oath, the palaver that he himself says his lawyer warned him to cut out of his Ervin Committee testimony because it’s too self-serving.