 Holmes and Watson then rescue Arneson, who was about to be sacrificed by a crazed cult member, and manage to retrieve an ancient book.Back in London, Holmes and Watson learn from the book about a mythical sea god who could be awakened by the sacrificing of persons representing the different nations.They also decipher Davy's numbers, which they find are co-ordinates pointing to Ardnamurchan Lighthouse on a Scottish coastline.