Haydon's interrogation reveals that he had been recruited several decades ago by Karla and became a full-fledged Soviet spy partly for political reasons, partly in frustration at Britain's rapidly declining influence on the world stage, particularly on account of the failings at the Suez. He is expected to be exchanged with the Soviet Union for several of the agents he betrayed, but is killed shortly before he is due to leave England. Although the identity of his killer is not explicitly revealed, it is strongly implied to be Prideaux, due to the method of execution echoing the way he euthanises an injured owl earlier in the book. Smiley is appointed temporary head of the Circus to deal with the fallout, and is still head at the start of the second book of The Karla Trilogy, The Honourable Schoolboy.