Frankie pushed open the door, ears tensed against the urgent clanging the bell made above the door and waited for the owner to make an appearance. In detective work, there are lines of enquiry that have all the makings of a rich lode – a seam of clues and evidence that if mined efficiently provide all you need to build a substantial case for the prosecution. The converse was also true, some seams may look promising and a disproportionate amount of energy is expended before the realisation dawns that you have a heap of fool’s gold in front of you. This seam didn’t even live up to the expectation of fool’s gold.

The old clockmaker appeared, pebble glasses perched on the end of his nose. He reminded her of Pinocchio’s cartoon father, Geppetto. She was about to start speaking loudly and clearly when he turned smartly on his heel and disappeared back into the depths of the shop, returning again with an elaborate mechanism suspended in a framework of old meccano metalwork. He wordlessly attached a small weight to a wire and started spinning a metal disc in the middle of the apparatus. The clockwork came alive, bone gears meshing together and moving in an almost silent mechanical ballet.

“There you are, my dear.” the old man announced. “It really is a quite accomplished work, if I say so myself. I’ve had to improvise, of course. The mechanism was almost intact but a lot of the supporting framework that held the gears in place was missing.”

“What does it do?” Frankie asked, her attention completely absorbed by the industrious apparatus standing on the counter in front of her.

“Well, I don’t have all the parts, of course, so I’d have to guess, and if I had to guess, I would say that it is a timing mechanism designed to operate this lever after a period of approximately one week from setting it.” He pointed at a piece of bone that jutted out of the mechanism. “It may have been holding this in the air.” He bent down to retrieve the bone harpoon that they’d first spotted on the track under the tree.

“Why would someone go to so much trouble to make a harpoon fall out of a tree? It doesn’t make sense?”

“I read in the paper that the young gamekeeper was killed by a snare?”

“That’s right.”

The old man peered at her through his glasses, eyes magnified alarmingly. “Well then, that bone could have pulled the snare down into place, ready to catch the young chap unawares.”

Frankie looked at him with surprise, even the most unlikely line of enquiry sometimes produced results. “Thank you. Thank you,” she repeated. “A week, you reckon, for this to run its course?”