Geoffrey Budworth has had a varied career as a high-ranking London policeman, as a principal officer in local government, and as a full-time lecturer at a large college of further education. He is now an author of non-fiction works with more than 20 books in the past 20 years to his credit-many about knots-and is a well-known name within the knotting fraternity. Richard Hopkins has worked in polymer technology research, banking, the security industry and industrial archaeology. He has too many hobbies, but knot-tying and lock-and- key collecting are the ones that interest him most.