When R. H. S. Crossman set out to break open the secret world of the Cabinet, he and his literary executors set in motion a process of challenges and negotiations which reveal a great deal about how constitutional conventions are articulated, protected and changed, who the lead actors in the process are, and where law fits in.  Archival research illuminates the roles of senior civil servants, Law Officers, the Treasury Solicitor, and politicians in managing a tightly focused series of conflicts over constitutional standards, and reveals the complexity of the forces which are commonly subsumed under the name of 'conventions'.  The story indicates that much of the UK's constitution is the product of continuously renegotiated, principled pragmatism maintained by our bureaucratic elite.