It's a blend of things, he’d said to Jason Diver, like a good whisky – the things that make a good detective. Active attention – concentrating, focusing, looking instead of just seeing. Then the informed expectation – using one’s experience and memories to forecast precisely, to make guesses that are intelligent. And the final thing? He had concluded, having thought about the matter too often over too many years, that it was ambition of imagination, by which he meant the critical ability
