 Complete the following phrase:  Back at Bletchley, Jericho joins the effort at deciphering contact reports and eventually produces a menu for the cryptanalytic bombes to work upon. He slips out and secretly deciphers the stolen cryptograms with the Enigma settings Hester has obtained. From these he learns the Germans have discovered thousands of bodies buried in the Katyn Forest. The corpses are those of Polish officers who must have been murdered by Britains ally, the Soviet Union, after it 