The Nail Biter This puzzle is based on the centuries old classic bent nails puzzle. Nobody is sure where the puzzle was invented, but is has been amazing puzzlers ever since with its infuriating mix of difficulty and simplicity. This version has an added twist to make it doubly difficult to solve.
					Nail Jail Slightly more difficult than the Nail Biter. The simplicity of this puzzle is well hidden, so it takes longer for even the most seasoned puzzler to get to grips with the mechanics of it.
					S-Nail If you manage to separate these two nails reasonably quickly don't be too quick to congratulate yourself. The fun really starts when you have to find a way to get them back together again. This puzzle is cunningly tricky to get to grips with.
					The Last Nail in the Coffin The most difficult of the four disentanglement puzzles. Two operations are required to sepa- rate and then reattach these nails. Only suitable for the more gifted puzzler.
					The Bed of Nails The Bed of Nails is the ultimate nail puzzle.Only when this puzzle has been solved without using our online clues and solution service can you claim to be a true master of Professor Puzzle nail puzzles. (Only available in the boxed set)