With these proofs of conspiracy in their hands, aided further by a small brown diary taken from the pocket of the dead man which had contained a full and damning resume of the whole plot, the Government had called an eleventh-hour conference.
The Government held a last minute conference because they had with them very important documents. 
mnli hypothesis: The Government held a last minute conference because they had with them very important documents.  premise: With these proofs of conspiracy in their hands, aided further by a small brown diary taken from the pocket of the dead man which had contained a full and damning resume of the whole plot, the Government had called an eleventh-hour conference.