"As to the identity of the source - well that's a big, big mystery at this stage, but so it should be… — John le Carré

"As to the identity of the source - well that's a big, big mystery at this stage, but so it should be. Forgive me if I'm a little wide of the mark here and there but I've only the file to go by."

The mention of a file, the first indication that Smiley might be acting in some official capacity, produced in Esterhase a discernible response…an expression of shrewd familiarity, as if Toby was trying to indicate that he too had read the file, whatever file it was, and entirely shared Smiley's conclusions.

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