`Look at that!' said Beverley, pointing to some writing at the bottom of the map. `Madog ap Rhys, 1707.' Just then Mr Roberts arrived. He listened carefully to Giles's story. Then he took a map out of his pocket. It was exactly like the map that lay on the table. `I've always wondered how the dead man got that map,' he said. `It's very unusual. There is only one other copy, and that's in the museum in Caernarvon.' `And who was Madog ap Rhys?' asked Giles. `He was a rather strange, lonely old man,' said Mr Roberts. `He lived alone on the hillside and spent most of his time praying. He died in 1720. Of course that was before the landslide destroyed the path to Adwy−yr−Eryon. When− ever there was a mist, Madog ap Rhys walked among the hills in his long dark cloak, with his dog beside him. He drew this map. He always carried a copy about with him, to give to travellers who had lost their way. Some local people say that his spirit still walks among the hills, searching for lost travellers. But that's only a story. I don't take it very seriously.' `How sad!' said Giles, after Mr Roberts had drunk his coffee and left. `Madog ap Rhys was a good, kind man. He only wanted to help. But he led poor Stevenson to his death, and he almost killed me.'