Over the next four days the problem became an idee fixe, a hermetic obsession to which he would return at any available opportunity, picking at the knot with fingers that were increasingly numb with use. The puzzle enthralled him as little in his adult life ever had. Working at the knot he was deaf and blind to the outside world. Sitting in his lamp-lit room by night, or in the park by day, he could almost feel himself drawn into its snarled heart, his consciousness focused so minutely it could go where light could not. But despite his persistence, the unraveling proved a slow business. Unlike most knots he had encountered, which, once loosened in part, conceded the entire solution, this structure was so adroitly designed that prising one element loose only served to constrict and tighten another. The trick, he began to grasp, was to work on all sides of the knot at an equal rate, loosening one part a fraction then moving around to loosen another to an equal degree, and so on. This systematic rotation, though tedious, gradually showed results.

He saw nothing of Red, Brendan or Catso in this time. Their silence suggested that they mourned his absence as little as he mourned theirs. He was surprised, therefore, when Catso turned up looking for him on Friday evening. He had come with a proposal. He and Brendan had found a house ripe for robbery and wanted Karney as lookout man. He had fulfilled that role twice in the past. Both had been small breaking and entering jobs like this, which on the first occasion had netted a number of salable items of jewelry, and on the second several hundred pounds in cash. This time, however, the job was to be done without Red's involvement.